GIFT  OF 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  PUBLIC  WORKS  AND  BUILDINGS 
DIVISION  OF  HIGHWAYS 


BULLETIN  NO.  16 


Manual  on  Road  Construction 

For 
Resident  Engineers  and  Inspectors 


PREPARED  BY 

B.  H.  PIEPMEIER 

Engineer  of  Construction,  Division  of  Highways 


SPRINGFIELD,  ILLINOIS 

April,  1921 


STATE  OF  ILLINOIS 

DEPARTMENT  OF   PUBLIC  WORKS  AND  BUILDINGS 
DIVISION    OF   HIGHWAYS 


BULLETIN  NO.  16 


Manual  on  Road  Construction 

For 

Resident  Engineers  and  Inspectors 


Prepared  by 
B.  H.  PIEPMEIER, 

Engineer  of  Construction,  Division  of  Highways 
LEN  SMALL,  Governor 
C.  R.  MILLER,  Director 
THOMAS  G.  VENNUM,  Assistant  Director 
S.  E.  BRADT,  Superintendent  of  Highways 
CLIFFORD   OLDER,    Chief   Highway   Engineer 


BUREAU  CHIEFS 

F.  T.  SHEETS,  l-.ngineer  of  Design 

B.    H.    PIEPMEIER,    Engineer    of    Construction 

FRED  TARKANT,   r.ngineer  of  Maintenance 

H.  F.  CLEMMER,  Engineer  of  Tests 

D.  H.  CORNELL.  Superintendent  of  Machiner\ 

J.   M.   McCoy,  (7//V/  Clerk 


SPRINGFIELD,  ILLINOIS 

April. 


Oc 

4 


SCHNEPP  &  BARNES,  PRINTERS,  SPRINGFIELD.  ILL. 

51549— 3M 


GIFT 


CONTENTS. 


Para- 
graph.    Page. 

Preface     

Organization     • 9 

Bureau   chiefs    1  9 

District  engineers   2  9 

Assistant    engineers,    junior    engineers    and    highway    inspectors 3  9 

County  superintendent  of  highways 4  9 

Township    and    district    commissioners 5  9 

Duties  of  resident  engineers  and  inspectors- 
Sizing   up    job    6  9 

Acquaintance    and    publicity 7  10 

Locating    resident    headquarters 8  10 

Remaining    on    job    9  10 

Correspondence     10  10 

Transportation  to  and  from  work 11  11 

Field    equipment    12  11 

Examination     of     plans     and     specifications 13  12 

Locating   B.    M.'s    14  12 

Locating    balance    points 15  12 

Righ-of-way     16  12 

Corner   Stones 17  13 

Grading    stakes    18  13 

Earth    shrinkage     19  14 

Slope    stakes     20  14 

Super-elevating    curves    21  14 

Final    grade    stakes 22  14 

Contractor's    equipment    and    methods 23  15 

Giving   instructions    24  15 

Daily    routine    of    engineers    in    charge    of    road    construction 25  15 

Reports     26  17 

Weekly    reports 27  17 

Records    28  17 

Cost  records    29  17 

Records    of    underground    work 30  18 

Record    of    bridge    piling 31  18 

Extra    work     32  18 

Water    supply — 

Quantity    and    quality 33  19 

Deep    wells    and    reservoirs 34  19 

Pipe    line    1 35  19 

Pipe    connections     36  20 

Pump 37  20 

Road    bed — 

Subgrade     38  20 

Scarifying     and     shaping     39  21 

Wetting    subgrade     40  21 

Rolling   subgrade    41  22 

Unrolled    subgrade    42  23 

Driving    on    subgrade 43  23 

Porous    materials    for    subgrade , 44  23 

•     Tiling    subgrade 45  23 

Oiling    subgrade    46  23 


4&4-2J3 


CONTENTS— Continued. 

Para- 
graph. 

Frozen    subgrade     47 

Materials   on   subgrade    48 

Backfilling  trenches  and  bridge  abutments 49 

Laying  pavement — 

Concrete    mixer    50 

Timing    devices     51 

Charging  mixer   52 

Installation    of    corrugated    joints 53 

Tie     bars     54 

Subgrade   templates    55 

Header    boards     56 

Noon   day   construction  joints 57 

Construction     joints 58 

Late   fall  construction 59 

One-half   of  pavement  built   at   a    time 60 

Side    forms    for   pavements 61 

Proportioning  aggregates   and   cement 62 

Combination    truck    and    industrial    railroad    delivery 63 

Team    delivery    to    mixer 64 

Proportioning  materials   in  batch  boxes 65 

Cement — 

Protecting  cement  in  transit  to  mixer 66 

Bulk  cement    67 

Cement   in   sacks    68 

Damaged   cement    69 

Cement    records    and    reports 70 

Cleaning    cement    sacks 71 

Storing    cement     72 

Cement    tests    73 

Borrowing    or    buying    cement 74 

Materials- 
Material     tests     - 75 

Storing    material    76 

Central    mixing    plants 77 

Hauling  mixed   concrete 78 

Consistency   of    mixed    concrete 79 

Finishing     mixed     concrete 8ft 

Finishing    concrete    pavements — 

Finishing    machine    81 

Checking    finished    surface 82 

Overtamping  surface    83 

Final  finish   84 

Hand    roller    and    belt , 85 

Finishing  curves    86 

Use    of    10-foot     straight    edge 87 

Character  of  finished  pavement 88 

Special     sections — 

Curb  and  gutter  sections 89 

Curb    and    gutter    turnouts 90 

Grate    bars    91 

Gutter   sections    92 

Curing     93 

Ponding  method  of   curing 94 

Use    of    straw    for    curing 95 

Earth     covering     96 

Protecting   pavement   by   use    of   frames    and    canvas 97 

Experimental    methods    of    curing    pavements 98 

Fall     and     spring     curing 99 

Protecting    surface    in    freezing    weather 100 

Preventing    concrete    from    freezing 101 

Monolithic    brick    pavements 102 


CONTENTS— Concluded. 

Para- 
graph.    Page. 

Finishing   base    course •  103  48 

Finishing    brick    surface    104  49 

Grouting    brick    surface 105  49 

Uniform   surface    106  50 

Curing 107  50 

Bituminous  filled  brick   construction — 

Concrete    base    108  50 

Curing    base 109  50 

Gravel  and   macadam   bases 110  50 

Cushion    HI  50 

Laying     and     rolling     brick 112  51 

Bituminous    filler    113  51 

Curing  surface   114  51 

Bituminous    concrete    pavements — 

Finishing    base    115  51 

Curing     116  52 

Concrete    curb    117  52 

Binder    and    wearing    courses 118  52 

Gravel    roads     119  53 

Trench    and    feather-edge    construction 120  53 

Crown     121  54 

Macadam  roads    122  54 

Crown     123  55 

Bituminous    macadam    roads 124  55 

Surface   treatment 125  55 

Surface    treating    gravel    roads 128  56 

Earth    roads 127  56 

Grading    machinery     128  57 

Earth    road    maintenance 129  57 

Oiled    earth    roads 130  57 

Shoulders   and   side   ditches — 

Cross   sections    131  58 

Side    ditches 132  58 

Hand    work    133  58 

Finishing    shoulders    134  59 

Entrance     culverts     135  59 

Acceptance    of    work 136  59 

Completing     details     of     work 137  59 

Certified    checks     138  60 

Partial    acceptance    139  60 

Payment    estimates     140  60 

Payment    for    materials    141  61 

Freight    increase    and   reductions 142  62 

Semi-final   estimates    143  62 

Affidavit     144  62 

Detour  and   barricade   signs 145  68 

Warning  sign 146  68 

Roal    closed     147  68 

Detour    signs 148  68 

Purchasing  and  erecting 149  68 

Maintenance    of    signs 150  ^68 

Maintenance   of    detour   road 151  69 

Barricades 152  69 


LIST    OF    ILLUSTRATIONS. 
Fig. 
No.  Page. 

1.  Temporary  reservoir  adjacent  to  deep  well  to  hold  surplus  water  during  paving  operations  19 

2.  Preparing   subgrade  .in    advance    of    a    paving    mixer 21 

3.  Horse  roller   coupled   to   caterpillar    tractor  and    used   for   rolling   subgrade 22 

4.  Material   stored   at  intervals   of   600   feet   along   the   side   of  the   road.      Short  industrial 

track    delivers    material    from    storage    piles    to    paving    mixer 24 

5.  One    and    one-half    ton    pneumatic   tired    truck    delivering    mixed    concrete    from    central 

plant  to  road 31 

6.  Aggregate   stored    on   top    of    a    tunnel   permits    a    large    storage    of    material   and    easy 

method    of    filling    batch   boxes    on    industrial    railroad    equipment 31 

7.  Concrete    pavement    cured    by    ponding    method.      Note    tunnel    and    material    yard    and 

cement  storage   bins   in   background 32 

8.  Material  plant  for  central  proportioning  batch  boxes  for  industrial  railroad  delivery 32 

9.  Transfer    station    for   material    boxes    from    trucks    to    industrial    cars.      Industrial    cars 

deliver    materials   to   paving    mixer   about    one    mile    ahead 33 

10.  One-ton    truck    loaded    with    mixed    concrete    being    turned    on    subgrade 38 

11.  Central  mixing  plant   38 

12.  Porous    spots    in    concrete    surface    can    be    avoided    if    a    small    amount    of    concrete    is 

kept   in  advance   of  the   templet  when  the   finishing   machine    is   moved   forward 40 

13.  Ten-foot    straight    edge    shows    up    a    depression    of    three-fourths    inch    in    the    finished 

surface     41 

14.  Slope-wall    construction    to    protect    road    from    excessive    erosion 42 

15.  Curb  and  gutter  outlet  at  bottom  of  steep  grade 43 

16.  Gutter   section    on    steep    grade    and   through    a    heavy    cut 44 

17.  Curb  and  gutter  construction  on  steep   grades  and  through  heavy   cuts 44 

18.  Canvas    covering   on   newly   laid    concrete    pavement   to    protect   it    from   sun   and    wind. 

Canvas   should   be    kept   wet    when    weather    is    extremely    hot 45 

19.  Canvas   covered   frames   used   to   cover  a   concrete   road    immediately   behind    the   paving 

mixer 46 

20.  Monolithic    brick    road    showing    concrete    base    and    brick    surface    being    finished    with 

a   mechanical   tamping   and    finishing   machine : 49 

21.  Corrugated    hand    roller   used    to    roughen    concrete    surface    for    a    bituminous    concrete 

pavement    51 

22.  Dumping,    spreading,   and   rolling   bituminous    concrete    on    a   concrete    base 52 

23.  Trench  method  of  constructing  macadam  or  gravel  roads 53 

24.  Gravel   road    constructed    by    the    feather-edge    method 54 

25.  Method  used    for   distributing   bituminous   material    for    surface    treatment   of    macadam 

and    gravel    roads    or    for    oiling    earth   roads 55 

26.  Condition  of  macadam  surface  after  first  application  of  one  and  one-half  to  two   gallons 

per   square   yard    of   bituminous    material   is    applied.     This   treatment   to    be    followed 
with   stone   chips   or  torpedo   gravel  then   one-half   to    three-fourths    gallon   per  square 

yard  and  another  covering  of  stone  chips  or  gravel 56 

27.  Well  graded   and   oiled   earth  road 58 

28.  Showing   well    shaped    shoulder   and   side    ditch 59 

29.  Itemized  material   statement  and  affidavit 63 

30.  Memorandum    of    cars    received 64 

31.  Excess   freight   and   war  tax   affidavit 65 

32.  Release    for   semi-final    estimate    65 

33.  Contractor's    affidavit     66 

34.  Suggested   form    of   bill   for   extra   work 67 

35.  Road   closed    sign    showing    engineer's   notations 70 

36.  Standard   warning   sign   for  barricades 71 

37.  Standard   detour   sign    showing   engineer's   notations    before    erecting 72 

38.  Map    showing    positions    of    barricade    and    detour    sign 73 


PREFACE. 

The  purpose  of  this  bulletin  is  to  set  forth  briefly  the  require- 
ments of  the  Department  of  Public  Works  and  Buildings,  in  the  con- 
struction of  various  types  of  roads.  It  must  be  understood  that  all 
preliminary  work  in  the  location  of  right-of-way,  surveys,  plans  and 
specifications,  regardless  of  the  time  or  talent  employed  in  the  prepara- 
tion of  the  work,  may  be  useless  if  the  construction  is  not  intelligently 
and  fairly  executed.  During  the  next  ten  years  it  is  estimated  that 
one  hundred  million  dollars  will  be  spent  for  road  improvement  in 
Illinois.  It  is  very  important,  therefore,  that  all  work  be  done  in  ac- 
cordance with  approved  principles  and  under  intelligent  supervision 
in  order  that  the  burden  imposed  by  future  maintenance  may  be  re- 
duced to  a  minimum. 

No  set  of  rules  and  no  set  of  specifications  can  be  written  to 
cover  completely  all  conditions  which  may  arise.  Experience,  judg- 
ment, and  integrity  in  carrying  out  the  requirements  of  the  specifica- 
tions must  dictate  the  answer  to  many  doubtful  questions  that  may 
arise  in  the  construction  of  the  work. 

It  is  hoped,  therefore,  that  this  bulletin  may  offer  suggestions  that 
will  aid  both  the  engineer  and  the  contractor  in  the  successful  com- 
pletion of  his  work. 


ORGANIZATION. 

The  purpose  of  the  revised  road  and  bridge  law  is  to  provide  a 
competent  organization  for  the  efficient  handling  of  all  road  and 
bridge  work  in  the  State.  Under  the  Civil  Administrative  Code  the 
Director  of  the  Department  of  Public  Works  and  Buildings  directs 
the  work  of  the  Division  of  Highways.  The  Superintendent  and 
Chief  Highway  Engineer  of  the  Division  of  Highways  in  conjunction 
with  the  Director  and  the  Board  of  Highway  Advisors  determine  the 
location  and  direct  the  design,  construction,  and  maintenance  of  all 
State  road  and  bridge  work. 

All  of  the  above  named  officials  are  appointed  by  the  Governor. 
All  other  employes  connected  with  the  Division  of  Highways  are 
under  Civil  Service. 

1.  Bureau  Chiefs.     For  convenience  and  efficiency,  the  work  of 
the  Division  is  administered  through  six  Bureaus ;  namely,  the  Bureau 
of  Design,  Bureau  of  Construction,  Bureau  of  Maintenance,  Bureau 
of  Tests,  Bureau  of  Machinery,  and  Bureau  of  Audits.     All  matters 
according  to  the  class  of   work  involved  should  be  referred   to   the 
bureau  in  charge  of  the  particular  work  in  question. 

2.  District  Engineers.     To  facilitate  field  work,  nine  geographic- 
al districts  have  been  established  with  a  district  engineer  in  charge  of 
each  district.     They  represent  the  State  in  all  field  work  pertaining  to 
road   and   bridge   construction    and   maintenance    in    their    respective 
districts  and  report  directly  to  the  bureau  chief  according  to  the  nature 
of  the  work  under  consideration. 

3.  Assistant  Engineers,  Junior  Engineers  and  Highway  Inspect- 
ors.    These  men  are  placed  on  one  or  more  sections  of  road  and  bridge 
construction  and  are  responsible  to  the  district  engineer  for  the  execu- 
tion of  the  work  in  accordance  with  the  plans  and  specifications. 

4.  County  Superintendents  of  Highways.     The  county  superin- 
tendents of  Highways  direct  all  county  and  township  work  and  are 
subject  to  the  rules  and  regulations  of  the  State  Division  of   High- 
ways.     Matters   which   they   wish   to   take   up   with   the   Department 
should  be  handled  through  their  district  engineer. 

5.  Township  and  District  Commissioners.     These  officials  have 
immediate  charge  of  all   work   within  their   respective  townships   or 
road  districts   subject  to  the  approval   of   the  county  superintendent 
of  highways. 

DUTIES    OF    RESIDENT    ENGINEERS    AND    INSPECTORS. 

6.  Sizing    up    Job.     In    the    execution    of    any    piece    of    work 
it  is  essential  that  proper  preparation  be  made  by  both  the  inspector 
or  engineer  in  charge  and  the  contractor  before  any  extensive  expendi- 


ture  of  time  or  money  is  made.  \Yhen  work  is  once  started  the 
money  allotted  or  available  for  its  execution  is  usually  spent  in  a 
comparatively  short  time.  The  contractor  and  engineer,  therefore, 
should  both  have  a  very  complete  understanding  of  the  plans  and 
specifications  and  of  all  conditions  surrounding  or  affecting  the  work 
before  active  construction  begins.  Considerable  lost  time,  effort,  and 
money  are  usually  the  result  of  misunderstanding  and  lack  of  know- 
ledge of  the  conditions  affecting  the  work.  The  successful  engineer 
or  contractor  will  therefore  spend  considerable  time  in  sizing  up  the 
job  in  all  of  its  details  before  starting  construction. 

T.  Acquaintance  and  Publicity.  The  resident  engineer  or  in- 
spector, after  sizing  up  the  job,  should  make  a  special  effort  to  be- 
come acquainted  with  the  leading  men  in  the  community.  It  is 
especially  important  that  you  call  upon  the  local  newspapers  and  give 
them  complete  information  in  regard  to  your  mission.  You  should 
also  make  a  special  effort  to  keep  them  informed  at  least  once  each 
week  in  regard  to  the  progress  of  the  work  and  any  other  items  of 
news  in  connection  with  the  construction  that  will  be  of  general 
interest  to  the  public.  In  giving  out  information  of  this  kind,  keep 
in  mind  that  you  are  an  employee  of  the  State  and  all  statements  made 
should  reflect  the  attitude  of  the  State  and  not  your  personal  ideas 
concerning  the  work  in  question. 

8.  Locating  Resident  Headquarters.     \Yhen  assigned  to  a  resi- 
dent job,  advise  the  telephone  and  telegraph  offices  immediately  where 
you  may  be  located.     You  will  make  a  special  effort  to  locate  your 
lodging  headquarters  at  a  place  where  you  may  be  reached  readily  by 
telephone  or  telegram  and  by  anyone  who  will  naturally  wish  to  call 
upon  you  for  information  relating  to  the  work.     You  will  also  try  to 
locate  as  near  to  your  work  as  possible  or  at  a  place  convenient  for 
transportation  to  and  from  the  job.     A  private  rooming  house  will 
give  you  a  much  better  rate  and  will  usually  prove  more  satisfactory 
than  the   average   hotel.      If    necessary   to    stay    at   a   hotel,    reduced 
wreekly  rates  should  be  secured.     You  will  not  always  be  able  to  se- 
cure meals  at  a  private  boarding  house  on  account  of  your  irregular 
hours  during  the  construction  season.     It  may  be  necessary,  therefore, 
for  you  to  plan  for  your  meals  at  restaurants  and  hotels.     Keep  in 
mind  that  inspection  costs  shall  be  kept  as  low  as  possible  consistent 
with  reasonably  good  living  conditions. 

9.  Remaining  on   the  Job.     You  are  expected  to  be  on  the  job 
at  all  times  while  construction  operations  are  in  progress.     If  abso- 
lutely necessary  to  be  off  the  job,   secure  permit   from   your  district 
engineer  and  then  choose  a  time  when  the  least  important  operations 
are  under  way.     When  important  construction  operations  are  in  pro- 
gress, watch  every  detail  regardless  of  the  time  or  hours  it  may  take. 
The  Department  expects  you  to   watch  all   phases  of   the  work.     If 
this  requires  more  time  than  you  are  physically  able  to  give  to  it,  the 
Department  will  furnish  you  additional  help. 

10.  Correspondence.     All  correspondence  relating  to  your  work 
shall  be  addressed  to  your  district  engineer.     It  shall  be  identified  by 


11 

placing  at  the  top  of  each  letter  the  subject  matter  and  the  section, 
county,  and  project  or  route ;  e.  g.  "Cement,  Sec.  I,  Madison  Co., 
Project  8"  or  "Estimate,  Sec.  H,  Greene  Co.,  S.  A."  Do  not  refer 
to  more  than  one  section  or  main  subject  in  any  one  letter. 

11.  Transportation  to  and  from  Work.     When  a  State  automo- 
bile is  assigned  to  you,  you  will  be  held  responsible  for  its  safe  keep- 
ing and    for   its   being   in   reasonably   good   running   condition   at   all 
times.     Small  ordinary  repairs  shall  be  made  promptly.     The  district 
engineer  shall  be  consulted  before  extensive  repairs  or  overhauling  are 
authorized.     Except  in  emergencies,  tubes   and  casings   will  be   fur- 
nished from  the  district  office  and  you  should  request  spare  tires  a 
sufficient  time  in  advance  of  your  needs  to  make  it  possible  for  them 
to  be  secured  from  the  superintendent  of  machinery  at  Springfield.    In 
purchasing  gasoline,  oil,  and  other  automobile  supplies,  receipted  bills 
shall  be  obtained  and  submitted  to  the  district  office  at  the  time  you 
submit  your  expense  account.    They  shall,  however,  be  kept  and  listed 
separate  from  your  expense  account. 

After  an  automobile  is  assigned  to  you  it  shall  be  used  exclusively 
for  State  business.  If  it  is  found  you  are  using  a  State  car  for 
pleasure  and  private  purposes,  it  will  be  evidence  that  you  do  not 
respect  the  rules  of  the  Department  and  will  be  sufficient  grounds  for 
dismissal  from  the  service. 

12.  Field  Equipment.     Resident   Engineers,   before   leaving  the 
district   office   should   generally   provide   themselves   with   the   fol- 
lowing supplies  and  equipment : 

Letter  heads,  envelopes,  postage 
Pencils  and  lumber  crayon 

1  Meld  book,  Cost  record  book 
Itemized  expense  book 

Sub- voucher  blanks 

Tax  exemption  certificates 

Daily  Report  Cards 

Weekly  progress  report  blanks 

Weekly  cement  report  cards 

Set  of  Plans  of  the  road  to  be  improved 

Transit,  tripods,  plumb-bob  and   reading  glass. 

Level  rod,  range  pole 

100  ft.  engineer's  steel  tape 

50  ft.  steel  tape 

50  ft.  metallic  tape 

Straight  edge 

Automobile 

2  spare  casings 

2  spare  inner  tubes 
Equipment  and  tools. 

When  additional  supplies  are  needed,  make  request  by  letter  to 
the  district  engineer. 

All  survey  instruments,  tapes,  chains,  rods,  etc.  when  taken  from 
the  office  are  charged  to  your  account  and  the  department  numbers 


12 

recorded.      No   equipment   shall   be   taken  out   of   the   office   without 
a  record  being  made  of  the  charge. 

Transits  and  levels  should  be  removed  from  the  tripods  and  kept 
in  the  box  at  night  and  when  not  in  use  they  should  be  left  in  a  safe 
place,  preferably  in  your  own  room.  The  practice  of  leaving  the  in- 
strument on  the  tripod  and  setting  it  in  a  farm  yard,  out  building,  or 
residence  is  carelessness.  Tapes  and  chains  should  be  cleaned  and  oiled 
occasionally  to  prevent  rusting  and  rods  should  be  handled,  carried  and 
shipped  in  a  manner  that  will  preserve  the  paint  and  the  numerals. 
Any  employee  of  ordinary  engineering  training  will  appreciate  the 
value  of  such  equipment  and  will  try  to  preserve  it  accordingly. 

13.  Examination  of  Plaits  and  Specifications.     You  will  secure 
from  your  district  engineer  a  complete  set  of  the  plans  and  specifica- 
tions for  the  work  to  which  you  have  been  assigned.     You  will  then 
take  the  plans  into  the  field  and  go  over  all  parts  of  the  work  not- 
ing in  your  permanent  memorandum  book  items  which  are  in  ques- 
tion or  which  you  think  should  be  taken  up  with  your  district  engi- 
neer.    Make  sure  that  you  fully  understand  all  of  the  requirements 
of   the  plans   and   specifications.      If   there   are   any   discrepancies   or 
points  which  are  not  clear,  do  not  hesitate  to  make  a  memorandum 
of  them  and  get  into  communication  immediately  with  your  district 
engineer.     Make  a  special  effort  to  go  over  all  details  of  the  plans 
and  specifications  with  the  contractor  or  superintendent  in  charge  of 
the  work.     If  there  are  any  points  which  are  not  entirely  clear  to 
the  contractor,   it   is   necessary  to   explain   them   and   to   reach   some 
agreement  concerning  the  execution  of  the  work  before  active  con- 
struction is   begun. 

14.  Locating  B.  M.'s.     Before  doing  any  survey  work,  you  will 
check  your  transit  and  level   for  adjustments.     You   will   then  locate 
on  the  ground  all  B.  M.  and  P.  I.  which  are  referred  to  on  the  plans 
and   check   them   carefully   to   make   sure   they   agree   with   the   nota- 
tions on  the  plans.     When  checking  B.  M.  and  P.  I.,  you  will  arrange 
to  set  other  B.  M.  at  intervening  points  so  that  you  will  have  a  B.  M. 
about  every  one  thousand   feet   and  one  at  each  cross   road  culvert. 
Special  care  should  be  taken  to  locate  B.  M.  and  P.  I.  so  that  they 
will  not  be  disturbed  by  grading  operations. 

15.  Locating  Balance  Points.     Before  any  grading  is  done  you 
will  mark  by  means  of  a  pole  or  otherwise  all  balance  points  through- 
out the  length  of  the  road.     This  is  very  necessary  for  the  contractor 
so  that  he  may  move  the  earth  in  the  right  direction  thereby  eliminat- 
ing future  trouble  with  regard  to  shortage  or  surplus  of  earth  when 
completing  the  work. 

Before  any  grading  or  bridge  work  is  done  you  will  ascertain 
the  amount  of  road  that  W7ill  have  to  be  detoured  by  traffic  and  then 
arrange  to  erect  the  necessary  detour  signs  in  accordance  with  in- 
structions found  in  paragraphs  145  to  151. 

16.  Right-of-Way.     Before   grading   is    started    you    will    check 
the  right-of-way  lines  of  the  entire  road.     Where  additional  right-of- 
way  has  been  secured  you  will  set  stakes   for  the  new  right-of-way 


13 

fence  line  and  notify  the  property  owner  in  writing  to  remove  the  fence 
at  least  fifteen  days  in  advance  of  the  time  you  expect  to  disturb  the 
road  at  that  particular  point.  You  will  also  communicate  with  your 
district  engineer  in  regard  to  all  poles  or  other  obstructions  within  the 
limits  of  the  graded  roadway  so  that  he  may  notify  the  utility  com- 
panies in  writing  to  clear  the  right-of-way.  Utility  companies  should 
be  notified  a  sufficient  time  in  advance  of  construction  work  to  enable 
them  to  have  the  right-of-way  cleared. 

17.  Corner  Stones.     Before  any  grading  operations  have  been 
started,  you  will  arrange  to  locate  if  possible  all  permanent  survey 
monuments  such  as  right-of-way  and  section  corner  stones.     The  sec- 
tion corner  stones   are  permanent  points  and   should   in  no   case  be 
disturbed  without  proper  record  being  taken  of  their  exact  location 
in  order  that  the  monument  may  be  re-established  in  the  finished  work. 
1  f  you  are  not  able  to  locate  section  corner  stones  you  will  get  into 
communication  with  the  county  surveyor  or  county  superintendent  of 
highways  who  will  assist  you  in  the  location  of  the  monuments.     Any 
expense  incurred  by  the  county  surveyor  in  locating  section  corner 
stones  will  be  borne  by  the  State.     It  will  be  your  duty,  however,  to 
reference   the   monuments    in    such   a   manner   that   they   can   be   re- 
established in  the  finished  work.     In  case  the  pavement  covers  the 
corner  stone,  a  cast  iron  plug  six  inches  square  and  three  inches  thick 
with  a  cross  upon  its  face  shall  be  accurately  set  in  the  surface  of  the 
finished  pavement  and  such  information  given  to  the  county  surveyor 
for  his  permanent  record. 

18.  Grading  Stakes.     Grading  stakes  will  be   furnished  by  the 
contractor  and  should  ordinarily  be  set  in  accordance  with  his  wishes. 
In  general,  they  will  be  set  at  intervals  of  one  hundred  feet  along  the 
fence  line  and  the  proper  cut  and  fill  for  the  finished  pavement  indi- 
cated on  them.     Ordinarily  stakes  on  one  side  of  the   road  will  be 
sufficient  for  the  preliminary  grading  work.     In  some  instances,  how- 
ever, the  contractor  will  wish  stakes  on  both  fence  lines  so  that  he 
may  "T"  across  the  road  for  his  intermediate  points.     Extreme  care 
should  be  exercised  in  locating  and  marking  preliminary   stakes   so 
that  they   will  not  be   disturbed,   and   so  that  they  will   contain  the 
proper  information  in  regard  to  the  grade    line    to    be    established. 
Changing  grade  stakes   frequently   results   in   considerable  delay  and 
expense  to  the  contractor.     In  addition  to  the  grade  stakes  set  along 
the  property  line,  the  contractor  will  usually  wish  a  line  stake  in  the 
center  of  his  road  at  intervals  of  300  or  400  feet. 

On  curves  it  will  be  necessary  to  set  stakes  at  intervals  of  25 
to  50  feet  on  both  sides  of  the  road,  preferably  about  fifteen  feet  from 
the  center  line  of  the  pavement  so  that  the  grading  foreman  may  es- 
tablish the  proper  super-elevation  at  the  time  the  grading  work  is 
being  done.  Grade  stakes  in  general  should  show  the  cut  or  fill  to 
the  finished  pavement  and  not  to  the  subgrade.  This  would  not  be 
true  with  an  earth  grading  section,  however,  as  the  stakes  in  this  case 
would  show  the  finished  grade  of  the  earth  work. 


14 

19.  Earth  Shrinkage.     In  no  case  should  grade  stakes  show  the 
shrinkage  that   should   be   provided   in   fill   sections.      Shrinkage   will 
vary  from  10  to  35  per  cent  depending  upon  the  character  of  the  soil 
and  the  way  the  fills  are  made.     The  engineer  shall  therefore  show 
the  finished  grade  line  elevation  and  require  the  contractor  to  allow 
sufficient  excess  of  material  to  provide  for  the  shrinkage.     In  general, 
where  earth  grading  will  average  from  2000  to  3000  cubic  yards  per 
mile  of  road,  25  to  35  per  cent  should  be  allowed  in  cut  over  fill  to 
provide  for  waste  and  shrinkage.     On  work  where  grading  will  aver- 
age from  3000  to  8000  cubic  yards  per  mile  of  road,  15  to  25  per  cent 
should  be  allowed  in  cut  over  fill.     On  grading  that  will  average  from 
8000  to  12000  cubic  yards  per  mile,  10  to  18  per  cent  should  be  al- 
lowed for  cut  over  fill.     If  the  excavated  material  is  sandy,  7  to  JO 
per  cent  of  cut  over  fill  will  usually  provide   for  the  shrinkage.     It 
should  be  kept  in  mind  that  excavation  in  rock  will  swell  from  .">  lo  20 
per  cent  over  the  fill  section. 

The  above  figures  are  only  approximate  and  will  vary  material]}' 
with  the  character  of  the  soil  and  the  methods  used  by  the  contractor 
in  making  the  fills. 

20.  Slope  Stakes.     In  all  cuts  and  fills   exceeding    three    feet, 
stakes  shall  be  set  at  the  toe  of  the  slope.    The  location  of  these  stakes 
shall  be  computed  from  actual  instrument  readings  at  the  point  where 
the  stake  is  set,  and  should  be  accurate  to  the  nearest  tenth  of  a  foot. 
The  stake  shall  indicate  the  cut  or  fill  for  the  finished  grade  disre- 
garding the  shrinkage. 

21.  Super  elevating  Curves.     All  curves  shall  be  staked  in  such 
a  manner  that  the  proper  superelevation  will  be  made  when  the  road 
is  graded.     TJnless  otherwise  noted  on  the  plans  the  superelevation 
will  commence  150  feet  from  the  P.  C.  and  attain  the  maximum  at 
the  P.  C.    The  center  line  of  the  pavement  shall  follow  the  true  grade 
as  shown  on  the  plans.    The  inside  of  the  curve  shall  be  depressed  one- 
half  of  the  amount  of  the  superelevation  and  the  outside  of  the  curve 
raised  one-half   of  the  amount  of   the  superelevation.     Supereleva- 
tion should  extend  from  shoulder  line  to  shoulder  line. 

22.  Final  Grade  Stakes.     Final  grade  stakes  should  be  set  true 
to  line  and  grade  at  intervals  of  50  to  100  feet  on  both  sides  of  the 
center  line  of  the  pavement  and  usually  about  two  feet  from  its  edge. 
In  many  instances  one  line  of  stakes  is  sufficient  as  a  good  form  setter 
can  transfer  the  grades  to  the  form  on  the  opposite  side  of  the  road 
with  an  ordinary  carpenter's  level. 

On  horizontal  and  vertical  curves,  finished  grade  stakes  should 
be  set  at  intervals  of  25  feet.  On  tangents  where  there  are  no  vertical 
curves,  the  grade  stakes  should  be  set  by  establishing  points  at  inter- 
vals of  400  or  500  feet  and  then  locating  all  intermediate  grade  stakes 
by  the  shooting  method.  On  curves  a  chalk  line  should  be  strung  on 
all  stakes  established  and  a  careful  inspection  of  the  alignment  and 
grade  made  with  the  eye.  If  the  alignment  and  grade  does  not  look 
right,  it  probably  is  wrong  and  should  be  checked  carefully  with  the 
instrument,  or  the  stakes  should  be  shifted  by  eye  so  that  the  pave- 


15 

ment  will  fit  the  ground  and  give  the  proper  appearance.  Make  it  a 
rule  to  reference  as  many  stakes  on  the  job  as  possible  as  a  great 
many  of  them  will  be  disturbed  by  construction  operations  and  you 
may  be  called  upon  frequently  by  the  contractor  to  establish  the  grade 
when  in  many  cases  you  have  only  a  limited  amount  of  time.  Use  your 
eye  frequently  in  checking  stakes  set  with  an  instrument.  This  will 
often  catch  errors  and  relieve  you  of  embarrassment  and  save  the  con- 
tractor delay  and  expense. 

23.  Contractor's  Equipment  and  Methods.     Do  not  discuss  pro- 
miscuously with  the  general  public  the  methods  of  the  contractor  or 
the  equipment  which  he  is  using  on  the  job.    You  should  concern  your- 
self with  the  quality  of  the  work  produced  and  not  so  much  with  the 
methods  of  the  contractor. 

24.  Giving  Instructions.     You  should  refrain  from  issuing  orders 
or  giving  instructions  to  individuals  on  contract  work.     The  contract- 
or's foreman  or  superintendent  on  the  work  should  be  respected  and 
all  instructions  to  the  men  issued  through  him.     If  he  does  not  carry 
out  your  instructions  the  matter  should  be  taken  up  with  the  contractor, 
and  then  if  no  improvement  is  made,  it  should  be  reported  to  your 
district  engineer. 

DAILY  ROUTINE  OF  ENGINEERS  IN  CHARGE  OF  ROAD 

CONSTRUCTION. 

25.  The   following  daily   routine  of   an   engineer   in   charge  of 
road  inspection  work  is  given  merely  as  a  suggestion  that  he  may  not 
overlook  some  of  the  important  details  that  arise  on  practically  every 
section  of  work.     No  set  of  rules  or  specifications  can  be  written  to 
cover   completely   all   conditions   which   may   be   encountered   as   the 
routine    of    inspections    will    vary    considerably    with    different    jobs. 
Experience  and  good  judgment  must  dictate  your  actions  on  construc- 
tion work.     The   following  routine,   however,   shows   a   few   of   the 
fundamental  duties  of  the  engineer  and  should  be  followed  as  a  gen- 
eral guide  in  the  inspection  of  road  work. 

1.  Check  cars  received  at  the  unloading  station. 

2.  See  that  header  board  at  the  close  of  the  previous  day's  work 
is  removed. 

3.  See  that  subgrade  is  cleaned  up  behind  the  mixer. 

4.  Check   surface   of  pavement   with   a   ten-foot   straight   edge 
adjacent  to  the  construction  joint. 

5.  See  that  sufficient  grade  stakes  are  set  for  the  pavement  and 
the  rough  grading. 

6.  Check  alignment  of  forms  with  the  eye. 

7.  See  that  all  side  forms  have  a  substantial  bearing  and  have 
been  oiled. 

8.  Check  subgrade  in  advance  of  the  mixer. 

9.  Walk  back  over  the  past  two  weeks'  work  to  see  that  it  is 
being  cured  properly.     Set  some  form  of  a  marker  at  the  end  of  the 


16 

two  weeks'  work.     This  will  serve  as  a  guide  to  the  individual  who 
is  looking  after  the  curing  of  the  pavement. 

10.  Examine  the  material  arriving  on  the  job. 

11.  Check    quantity    of    material    in    batches    and    amount    of 
cement  used. 

12.  See  that  new  concrete  adjacent  to  the  construction  joint  has 
been  properly  edged  and  finished,  and  check  with  a  zo-foot  straight 
edge.    I  insist  upon  a  perfect  joint. 

13.  Check  alignment  and  grade  of  finished  pavement. 

14.  Use  a  lo-foot  straight  edge  on  forms  and  finished  pavement. 

15.  Check  revolutions  and  time  the  mixer  is  mixing  concrete. 

16.  Check  consistency  of  concrete. 

17.  See  that  the  tamping  machine  is  doing  its  work. 

18.  Record  number  of  men  working  on  subgrade,  forms  around 
mixer,  finishing,  curing,  etc. 

19.  Check  up  work  being  done  on  culverts  and  bridges  in  ad- 
vance of  the  paving  work. 

20.  See  that  all  the  previous  day's  work  has  been  covered  and 
sprinkled  or  is  being  cured  properly. 

21.  Check  alignment  of  forms  and  finish  of  pavement  completed 
during  the  day.     Use  a  10-foot  straight  edge. 

22.  Check  position  of  reinforcing  steel  in  pavement. 

23.  See  that  pavement  has  been  properly  edged. 

24.  See  that  all  concrete  is  thoroughly  spaded  and  that  there  are 
no  stone  pockets  in  the  road  or  adjacent  to  the  forms. 

25.  Measure  distance  between  the  construction  joint  and  noon 
day  header  board. 

26.  Check  total   number  of   batches   or   sacks  used   during   the 
morning's  work. 

27.  See  that  the  noon  day  header  board  is  properly  placed  and 
that  the  reinforcing  steel  is  in  place. 

Afternoon.  Repeat  all  operations  in  afternoon  except  those 
designated  in  paragraphs  1,  9,  19,  and  23,  and  in  addition  look  after 
the  following  items  of  work. 

28.  Check  shoulder  and  ditch  work  being  done  on  finished  pave- 
ment. 

29.  See  that  pavement  is  cleaned  after  the  two  weeks'  period 
of  curing. 

30.  See  that   new   pavement   is   being  covered   with    frames   or 
convas. 

31.  See,  if  possible,  that  all  barricades  and  detours  are  in  place 
before  leaving  work.     Inspect  all  detours  and  signs  at  least  once  each 
week. 

32.  Check  cost  items  on  all  force  account  work  with  the  super- 
intendent or  foreman. 


17 

33.  Measure  total  parement  laid  during  the  day  and  check  ce- 
ment sacks  used. 

34.  Make  daily  reports  and  record  all  data  necessary  for  weekly 
reports. 

REPORTS. 

26.  Daily   reports   shall  be   made  to  your  district   engineer   on 
blank  cards  furnished  for  this  purpose.     These  reports  shall  give  a 
brief  record  of  the  work  done  and  should  ordinarily  include  a  report 
of  materials  received,  grading,  work  done  on  bridges  and  culverts, 
pavement  laid,  weather  conditions,   etc.     One   report   shall  be  made 
for  each  mixer  in  operation  on  the  job. 

27.  Weekly  Reports.     Weekly  reports  shall  be  made  promptly 
after  the  close  of  the  work  Thursday  night.     They  should  be  in  the 
district  office  by  Saturday  and  in  the  Springfield  office  by  Monday. 
On  Federal  Aid  work  they  shall  be  mailed  to  the  district  office  in 
triplicate  so  that  one  copy  may  go  to  the  Federal  district  engineer, 
one  may  be   retained  by  the  district  engineer  and  one  sent  to  the 
Springfield  office.     If  you  do  not  keep  a  permanent  record  in  your 
notebook  of  the  progress  of  your  work,  you  shall  keep  a  copy  of  all 
weekly  reports  for  future  reference.     The  weekly  report  is  the  most 
important  of  all  the  reports  you  make  concerning  your  work.     For 
this   reason,   therefore,   the  man   supervising  your  duties   will   judge 
your  work  largely  by  the  reports  you  make.     All  of  the  blank  spaces 
provided  on  the  report  blanks  shall  be  filled  out.    Statistics  in  the  main 
office  are  kept  from  weekly  reports  sent  in  by  field  men.     You  will 
therefore  indicate  on  the  report  the  cause  for  no  work  being  done 
or  for  delays.     You   will   also   indicate   under  the   item   "Feet   Laid 
Per  Day"  whether  one  or  two  gangs  were  working  and  the  number 
of  mixers  used  during  each  day  pavement  was  laid. 

28.  Records.     The   Department  will   furnish  all   resident  engi- 
neers and  inspectors  with  a  field  notebook  in  the  form  of  a  survey 
book  or  construction  record  book  for  the  purpose  of  keeping  a  com- 
plete record  of  all  operations  in  connection  with  the  execution  of  the 
work  to  which  you  have  been  assigned.    The  notebook  is  the  property 
of  the  State  and  when  the  job  is  completed  or  when  the  book  is  filled 
should  be  filed  with  your  district  engineer  as  a  record  of  the  work 
done  by  you  in  connection  with  the  construction  of  the  road  or  bridge. 
The  book  shall  also  contain  your  name  and  address  and  the  address 
of  the  district  office  so  that  in  case  of  loss  it  may  be  returned  to  the 
proper  owner.    It  shall  be  made  up  in  such  a  manner  that  it  will  fur- 
nish you  with  all  of  the  information  desired  to  complete  your  weekly 
report.     A  memorandum  or  diary  of  the  operations  connected  with 
the  construction  of  a  road  or  bridge  shall  be  kept  in  a  book  as  a  mat- 
ter of   future  reference  in  case  of  disputes  or  for  information  that 
may  be  desired. 

29.  Cost  Records.  Keeping  cost  records  is  an  essential  part  of 
your  duty  if  you  can  secure  authentic  information.  Cost  record  books 
will  be  furnished  you  for  this  purpose.  Records  should  be  made  as 


18 

complete  as  possible  without  interfering  with  the  supervision  of  the 
construction  work  and  without  annoyance  to  the  contractor  or  his 
timekeeper.  Diplomatic  methods  may  enable  you  to  secure  some  valu- 
able data  on  specific  phases  of  the  contractor's  work.  In  many  cases 
contractors  will  cheerfully  give  information  in  regard  to  costs.  It  is 
not  always  advisable  to  keep  an  accurate  cost  of  all  phases  of  the  work 
but  pick  out  a  few  essential  operations  and  keep  an  accurate  cost  of 
them  so  as  to  enable  the  Department  to  compile  information  suitable  for 
making  future  estimates. 

30.  Records  of  Underground  Work.     You  shall  make  a  detailed 
report  in  your  permanent  notebook  of  all  substructure  work  in  con- 
nection with  the  construction  of  a  road  or  bridge.     In  case  tile  drains 
are  put  in,  the  stationing  and  exact  location  of  the  tile,  the  size,  depth, 
etc.  shall  be  recorded.    This  information,  as  soon  as  the  work  is  com- 
pleted, shall  be  reported  to  the  district  engineer  in  the  form  of  a  letter 
for  permanent  record. 

31.  Record  of  Bridge  Piling.    When  piles  are  driven  in  a  bridge 
foundation,  the  depth  and  width  of  the  footings,  and  the  character  of 
the  soil  encountered  shall  also  become  a  permanent  record.     This  in- 
formation shall  be  transmitted  to  the  district  engineer  in  the  form  of 
a  letter  setting  forth  the  number  of  piles  driven  in  each  bridge,  their 
size,  length  and  spacing,  the  character  of  the  soil,  the  depth  of  the  foot- 
ings, etc.    These  letter  records  of  substructure  work  are  made  so  that 
they  may  be  readily  referred  to  in  the  future. 

32.  Extra  Work.    Field  engineers  are  not  permitted  to  authorize 
extra  work  or  substantial  alterations  without  the  written  consent  of 
the  district  engineer  or  his  authorized  assistant.    Any  changes  appear- 
ing to  be  desirable  shall  be  brought  to  the  attention  of  the  district 
engineer  or  his  assistant  at  the  earliest  possible  date  so  that  the  correc- 
tion may  be  made  if  found  necessary.     On  all  force  account  or  extra 
work  you  will  keep  a  complete  daily  record  of  the  number  of  men  em- 
ployed and  materials  used.     At  the  close  of  each  day  you  will  check 
your  records  against  the  official  record  of  the  contractor's  foreman  or 
superintendent  and  in  case  of  discrepancies  make  adjustments  before 
proceeding  further  with  the  work.     If  it  is  impossible  to  check  each 
night  for  comparison,  a  check  shall  be  made  at  least  two  or  three  times 
each  week  to  make  sure  that  the  records  will  agree. 

Bills  should  be  presented  by  the  contractor  upon  completion  of  the 
extra  work,  or  at  least  once  each  month,  covering  all  extra  work  auth- 
orized. 

In  no  case  should  a  contractor  be  expected  to  do  extra  work  with- 
out a  written  order  from  you  or  the  district  engineer.  Extra  work  is 
often  the  cause  of  considerable  dispute  upon  final  completion  of  a  con- 
tract. You  should,  therefore,  take  great  pains  to  see  that  a  complete 
record  is  made  of  all  extra  work  and  that  your  records  conform  to  the 
records  taken  by  the  contractor's  superintendent  or  foreman. 


19 

WATER  SUPPLY. 

33.  Quantity  and  Quality.     The  contractor's  water  supply   for 
road  or  bridge  construction  is  a  very  vital  part  of  the  work  and  often 
affects  materially  the  progress  or  quality  of  the  construction.     Ordi- 
narily the  contractor  should  provide  10  gallons  per  square  yard  of 
pavement  for  the  operation  of  the  mixer  and  the  mixing  of  the  con- 
crete.   In  addition  he  will  require  from  fifteen  to  thirty  gallons  of  water 
per  square  yard  of  pavement  for  curing  purposes.     A  careful  investi- 
gation of  the  water  supply  therefore  should  be  made  early  in  the  sea- 
son so  as  to  make  sure  that  a  sufficient  quantity  may  be  provided  at  all 
times  to  complete  the  work  in  accordance  with  the  specifications.     It 
is  also  well  to  make  a  careful  examination  of  the  quality  of  the  water 
to  be  sure  that  it  is  not  injurious  to  the  concrete  or  to  the  steam  boil- 
ers in  case  steam  is  used  on  the  mixer. 

34.  Deep  Wells  and  Reservoirs.     In  general  deep  wells  cannot  be 
counted  upon  to  supply  water  for  the  average  road  job  although  in  some 
instances  they  are  the  only  source  of  water  supply  and  must  be  used. 
In  such  cases  it  is  desirable  to  construct  reservoirs  near  the  wells  so 
that  storage  may  be  provided  and  surplus  water  impounded  by  24 
hours'  pumping.     Economical  and  satisfactory  reservoirs  may  often 
be  constructed  by  excavating  a  hole  of  the  desired  capacity.    The  ex- 
cavated hole  having  side  slopes  of  about  one  and  one-half  to  one  may 
then  be  trimmed  until  smooth  and  the  entire  surface  plastered  with  a 
one  to  three  mortar  about  three- fourths  of  an  inch  in  thickness.    The' 
plastered  surface  should  be  protected  by  damp  straw  or  canvas  im- 
mediately after  its  application  to  prevent  it  from  cracking.    The  reser- 
voir may  be  filled  with  water  twelve  hours  after  it  is  finished. 


Pig.  1.  Temporary  reservoir  adjacent  to  deep  well  to  hold  surplus 
water  during  paving  operations. 

35.     Pipe  Line.     The  pipe  line  from  the  water  supply  to  the  mix- 
ing plant  or  road  should  be  of  sufficient  size  to  give  an  ample  supply 


20 

to  the  mixer  when  it  is  working  to  its  full  capacity.  It  is  not  always 
necessary  that  the  pipe  line  be  sufficient  to  supply  water  for  curing 
purposes  at  the  time  the  mixer  is  being  run  although  this  is  desirable. 
The  curing  can  usually  be  done  at  a  time  when  the  mixer  is  not  in 
operation.  The  pipe  line  should  contain  a  number  of  unions  so  that 
in  case  broken  pipe  is  encountered  a  new  section  may  be  installed  with- 
out undue  delay  to  the  work.  Expansion  joints  at  intervals  of  one 
thousand  to  two  thousand  feet  are  also  desirable  to  prevent  buckling 
or  breaking  of  the  pipe  line  during  hot  weather.  Regular  expansion 
joints  are  manufactured  by  pipe  and  pump  companies  but  may  be 
conveniently  made  by  installing  a  short  section  of  water  hose  at  the 
desired  intervals.  The  pipe  line  should  be  laid  to  one  side  of  the  road 
where  it  will  not  be  distributed  by  grading  operations.  It  should  be 
so  placed  as  to  have  the  advantage  of  the  shade  of  a  hedge  to  pro- 
tect it  from  the  heat  of  the  sun  and  also  laid  with  T's  and  plugs  at 
all  low  points  so  that  it  may  be  drained  readily  during  freezing 
weather.  In  some  cases  it  may  be  desirable  to  plow  a  furrow  to  re- 
ceive the  pipe  line.  The  earth  may  then  be  plowed  back  on  top  of  the 
pipe  line  and  the  water  thus  kept  much  cooler  during  the  hot  summer 
months  and  freezing  prevented  during  the  cool  nights  of  early  fall. 

36.  Pipe   Connections.     When  the  pipe   line   is   being  laid  you 
should  see  that  sufficient  "T's"  are  installed  at  intervals  of  200  to  500 
feet  to  provide  for  hose  connections  for  supplying  water  to  the  mixer 
and  for  curing  purposes.     Where  big  mixers  are  being  operated  it  is 
frequently  desirable  and  economical  to  install  two  independent  pipe 
lines,  one  for  the  mixer  and  the  other  for  curing  purposes. 

37.  Pump.     The  size  of  pump  for  different  jobs  wrill  vary  with 
the  amount  of  water  needed.    In  general,  the  30  to  40  gallon  per  minute 
pump  will  prove  to  be  sufficient   for  the  four-bag  mixer.     There  is 
a  great  deal  of  discussion  as  to  the  advantages  of  steam  vs.  gas  pumps. 
Where  gas  pumps  are  installed  it  is  usually  desirable  to  have  duplicate 
units  to  eliminate  trouble  and  delays.     The  one  and  one-half  or  two 
inch  pipe  line  used  with  the  ordinary  construction  pump  usually  limits 
the  distance  over  which  water  may  be  successfully  delivered  to  the 
mixer  or  road  job.    A  distance  of  three  miles  is  usually  the  maximum 
for  a  two-inch  pipe  line  with  grades  ordinarily  encountered.     When 
required  to  pump  this  distance  or  further,  it  is  desirable  and  usually 
necessary  to  install  a  booster  pump  at  some  convenient  point  in  the  line. 

ROAD  BED. 

38.  Subgrade.     A   uniform,    well    compacted,   properly    drained 
subgrade  has  perhaps  more  to  do  with  the  successful  completion  and 
life  of  a  pavement  than  most  any  other   factor.     Regardless  of  the 
type  of   wearing  surface  constructed,  the  subgrade  must  necessarily 
transmit  the  loads   from  the  pavement  to  the  earth.     The  subgrade 
should  be  recognized  as  that  portion  of  the  road   from  shoulder  to 
shoulder  of  the  graded  roadway.     It  should  be  shaped  and  crowned 
to  drain  the  water  readily  to  the  side  ditches  and  should  be  as  nearly 
uniform  in  character  as  is  possible  to  make  it  with  practical  methods. 


21 

In  general,  the  subgrade  that  is  made  by  the  use  of  teams  or  tractors 
requires  very  little  rolling  to  secure  sufficient  consolidation  for  the 
pavement.  The  frequent  use  of  a  road  drag  or  planer  will  usually 
leave  a  subgrade  in  condition  suitable  for  final  finishing  and  placing 
of  the  pavement.  Where  a  slight  amount  of  material  is  moved  in  the 
final  shaping  of  the  subgrade,  a  light  tandem  roller  will  iron  out  the 
surface  in  a  manner  that  prepares  it  satisfactorily  for  the  pavement. 
Special  care  should  be  taken  to  get  the  subgrade  thoroughly  compacted 
immediately  under  the  side  forms  and  for  a  distance  of  at  least  one 
foot  outside.  The  subgrade  beneath  the  forms  must  support  the  load 
that  is  applied  to  the  forms  and  prevent  settlement. 

39.  Scarifying  and  Shaping.  After  the  rough  grading  has  been 
done,  a  subgrader  or  scarifier  operated  in  connection  with  a  power  roller 
may  be  used  to  advantage.  In  some  instances  light  scarifiers  are  used 
and  pulled  by  independent  power.  In  either  case  it  is  advisable  to 
scarify  the  entire  surface  to  a  depth  of  at  least  two  inches  below  the 
finished  subgrade.  The  pulverized  material  may  then  be  uniformly 
spread  over  the  surface  to  the  desired  depth  and  the  surface  rolled 
lightly  to  bring  it  to  true  grade.  There  are  a  number  of  subgrading 
machines  which  may  be  used  after  the  surface  has  been  scarified  or 
loosened.  These  machines  operate  on  the  side  forms  and  trim  the  sub- 
grade  true  to  the  cross  section  shown  on  the  plans.  After  the  subgrade 
has  been  prepared  for  the  pavement,  it  should  not  be  rutted  by  trucks 
or  wagons  or  compacted  in  such  a  way  that  it  will  not  be  uniform  in 
character. 


Fig.  2.  Preparing  subgrade  in  advance  of  a  paving  mixer. 
40.  Wetting  Subgrade.  When  trucks  are  employed  very  little 
water  should  be  used  for  wetting  the  subgrade  in  advance  of  placing 
the  concrete  as  water  will  cause  some  mud  to  get  into  the  concrete. 
Under  normal  conditions  and  especially  where  materials  are  delivered 
by  industrial  quipment,  the  best  results  are  obtained  when  the  subgrade 
is  soaked  with  water  the  day  before  the  concrete  is  placed.  This 


22 

method  is  much  to  be  preferred  and  should  be  used  whenever  possible. 
The  purpose  of  wetting  the  subgrade  is  to  prevent  the  earth  from  ab- 
sorbing an  excessive  amount  of  moisture  from  the  concrete  during  the 
setting  process  and  to  allow  the  over-compacted  earth  in  the  subgrade 
to  swell  and  obtain  its  normal  condition  before  the  pavement  is  laid. 
41.  Rolling  Subgrade.  It  is  necessary  that  some  form  of  roller 
be  used  in  the  preparation  of  the  subgrade  for  the  pavement.  Under 
normal  conditions  the  light  3-ton  tandem  roller  will  prove  entirely 
satisfactory  for  this  purpose.  However,  the  ordinary  3  to  5-ton  horse 
roller  pulled  by  a  light  caterpillar  tractor  engine  will  also  meet  the 
requirements  of  the  specifications  and  prove  to  be  satisfactory.  In 
some  instances  the  10-ton,  3-wheeled  roller  will  be  used,  in  which  case 
it  should  go  over  the  subgrade  but  once  as  it  is  very  easy  to  over- 
compact  portions  of  the  roadbed.  In  such  case  the  subgrade  should 
always  be  soaked  12  hours  or  more  before  concrete  is  placed.  In 
general,  the  use  of  the  3-wheeled  heavy  type  roller  for  this  purpose 
should  be  discouraged.  Where  there  are  but  a  few  inches  of  loose 
material  to  be  compacted,  a  home-made  concrete  roller  or  a  hand 
roller  may  prove  to  be  sufficient  to  iron  out  the  subgrade  preparatory 
to  the  construction  of  the  pavement.  In  no  case  should  the  heavy 
3-wheeled  rollers  be  used  after  the  soil  has  been  saturated  with  water 
as  it  will  over-compact  the  earth  and  cause  trouble  in  the  swelling 
of  the  subgrade  after  the  pavement  is  placed.  The  heavy  rollers  and 
traction  engines  are  especially  desirable  for  compacting  large  fills  dur- 
ing the  process  of  construction.  The  3-wheeled,  10-ton  rollers  will 
locate  the  soft  spots  in  the  fill  and  assist  in  compacting  the  loose 
material  and  thereby  reduce  the  settlement  to  a  minimum.  When  fills 
are  built  up  in  horizontal  layers  of  approximately  18  inches  by  the 
use  of  wheel  scrapers,  slips  or  dump  wagons,  there  is  usually  no  ad- 
vantage in  rolling  the  fills  during  the  process  of  construction. 


Fig.  3.  Horse  roller  coupled  to  caterpillar  tractor  and  used  for  roll- 
ing subgrade. 


23 

42.  Unrolled  Subgrade.     In  case   the   subgrade  has  been   pre- 
pared for  a  distance  of  several  hundred  feet  in  advance  of  the  mixer 
and  there  should  be  a  heavy  rain  causing  an  undue  swelling  of  the  sub- 
grade,  no  attempt  should  be  made  to  roll  in  advance  of  the  mixer 
or  of  concrete  that  is  being  deposited.     In  this  case  the  use  of  a  sub- 
grading  machine  or  other  means  of  trimming  the  subgrade  true  to 
cross  section  before  the  concrete  is  deposited  is  sufficient.     The  sub- 
grade  is  in  an  ideal  condition  for  the  pavement  after  a  rain  or  after  it 
has  become  thoroughly  saturated  by  means  of  sprinkling  as  this  will 
cause  the  earth  to  swell  and  assume  its  natural  condition.     The  prin- 
cipal object  in  the  preparation  of  a  subgrade  is  to  secure  uniformity 
throughout.     Should  low  places  exist  they  may  be  filled  with  earth 
providing  they  are  compacted  the  same  as  the  remainder  of  the  road. 

43.  Driving  on  Subgrade.     There  is  no  objection  to  motor  trucks 
being  driven  over  the  subgrade  provided  they  are  not  loaded  to  such 
an  extent  that  the  subgrade  is  rutted  or  depressed  out  of  shape.  When 
trucks  are  used  for  dumping  directly  into  the  mixer  they  should  cover 
the  entire  surface  of  the  subgrade  in  order  to  compact  it  more  uni- 
formly throughout  its  full  width.     Narrow  steel  tires  or  teams  turn- 
ing or  backing  on  the  subgrade  shall  not  be  allowed.    When  trucks  are 
used  for  the  delivery  of  batches  direct  to  the  mixer  considerable  time 
will  be  saved  by  utilizing  a  turn  table  which  may  be  placed  on  the  sub- 
grade  a  few  hundred  feet  in  advance  of  the  paving  mixer.     Frequent 
backing  and  turning  on  the  subgrade  often  causes  large  ruts.     This 
should  be  avoided  wherever  possible.     There  are  a  few  truck  bodies 
that  are  built  so  as  to  dump  at  the  side  thereby  permitting  material 
to  be  dumped  directly  into  the  skip  of  the  mixer  before  the  truck 
is  turned  around.    This  method  permits  the  trucks  to  turn  when  empty. 
In  this  case  turning  on  the  subgrade  is  not  nearly  so  objectionable. 

44.  Porous  Material  for  Subgrade.   When  the  subgrade  is  poorly 
drained  it  may  often  appear  to  be  advantageous  to  roll  in  a  layer  of 
gravel,  stone  or  cinders  before  placing  the  pavement  thereon.     Gen- 
erally there  is  no  objection  to  this  method  of  obtaining  a  suitable  sub- 
grade,  but  in  such  instances  the  porous  material  beneath  the  pave- 
ment should  be  carefully  drained  or  it  will  act  as  a  reservoir  for  water 
and  thereby  result  in  additional  damage  to  the  pavement. 

45.  Tiling   Subgrade.     If    an    exceptionally   wet   subsoil   is   en- 
countered, it  may  be  remedied  by  intercepting  the  flow  of  underground 
water  by  the  installation  of  4  or  6-inch  tile  drains.    Such  tile  should  be 
placed  from  2^2  to  3  feet  in  depth  and  the  trench  backfilled  with  por- 
ous material.    A  single  line  of  tile  down  the  center  or  along  the  upper 
side  of  the  pavement  with  lateral  drains  at  various  intervals  along  the 
road  will  usually  prove  sufficient  to  drain  out  the  surplus  underground 
water.     When  two  lines  of  tile  are  used,  they  should  ordinarily  be 
placed  beneath  the  edges  of  the  pavement  to  a  depth  of  2  to  3  feet  and 
the  trench  backfilled  with  porous  material.     In  general  a  6-inch  tile  is 
a  desirable  size  to  use  for  the  draining  of  the  subsoil. 

46.  Oiling  Subgrade.     After  the  subgrade  has  been  prepared  it 
may  be  treated  advantageously  with  road  oil.    The  oil  will  keep  down 


24: 


the  dust  and  prevent  the  formation  of  ruts  and  mud  during  rainy 
weather.  It  will  make  possible  the  use  of  light  trucks  much  sooner 
after  a  rain  and  will  eliminate  the  necessity  of  wetting  down  the  sub- 
grade  prior  to  the  placing  of  the  concrete.  For  construction  pur- 
poses the  subgrade  may  be  oiled  for  a  width  of  15  feet.  This  would 
enable  trucks  to  follow  the  oiled  portion  of  the  road  in  the  delivery  of 
materials.  If  the  pavement  is  to  secure  the  full  benefit  of  the  oil 
the  subgrade  should  be  oiled  to  the  full  width  of  18  feet.  The  oil 
should  be  applied  as  early  in  the  spring  as  conditions  will  permit  and 
when  the  road  is  free  from  dust  and  loose  material.  It  should  be  ap- 
plied at  the  rate  of  one-half  gallon  per  square  yard  in  two  equal  appli- 
cations. The  cost  will  vary  but  may  be  estimated  at  $300  to  $600  per 
mile  of  road. 

The  subgrade  that  has  been  thoroughly  saturated  with  oil  will 
resist  the  raising  of  subsoil  water  by  capillary  attraction  and  will  pre- 
vent surface  water  from  softening  the  subsoil  immediately  beneath 
the  slab,  thereby  resulting  in  additional  stability  to  the  pavement. 

47.  Frozen  Subgrade.     Mixed  concrete  should  not  be  deposited 
upon  a  frozen  subgrade  for  the  reason  that  the  frost  will  be  drawn 
from  the  subgrade,  thus  lowering  the  temperature  of  the  concrete  be- 
low 40°   F.  and  preventing  it  from  obtaining  its  proper  set.     When 
there  is  but  a  small  amount  of  road  to  be  completed  during  freezing 
weather  the  subgrade  may  be  protected  from  frost  by  a  covering  of 
straw,  which  shall  be  removed  immediately  in  advance  of  the  deposit- 
ing of  the  concrete. 

48.  Materials  on  subgrade.     After  the  subgrade  has  been  pre- 
pared, no  materials  shall  be  dumped  upon  it  without  the  consent  of  the 
Chief  Highway  Engineer.    Aggregates  may,  however,  be  dumped  upon 


Fig.  4.  Material  stored  at  intervals  of  600  feet  along  the  side  of  the 
road.  Short  industrial  track  delivers  material  from  storage  piles  to 
paving  mixer. 


the  subgrade  or  at  the  sides  of  the  road  at  intervals  of  not  less  than 
400  feet  provided  the  material  is  placed  in  large  piles  and  not  spread 
out  over  the  subgrade  or  shoulders.  When  material  is  dumped  in 
this  way  it  should  be  piled  at  least  three  dumps  high  to  prevent  spread- 
ing and  to  avoid  a  surplus  of  earth  being  picked  up  when  it  is  re- 
handled. 

49.  Backfilling  trenches  and  bridge  abutments.  When  it  is 
necessary  to  backfill  a  trench  or  the  space  adjacent  to  a  bridge  abut- 
ment, special  effort  should  be  made  to  thoroughly  compact  the  earth. 
Numerous  pavement  failures  and  bridge  failures  are  traceable  directly 
to  negligence  in  this  important  operation.  The  backfill  must  be  made 
in  horizontal  layers  of  not  to  exceed  one  foot  and  each  layer  thoroughly 
compacted  by  means  of  rolling  or  hand  tamping  until  the  entire  fill 
is  completed.  In  trench  work  it  is  frequently  possible  to  fill  the  trench 
with  water  and  make  all  backfills  by  dumping  material  directly  into 
the  water;  much  better  results  will  be  obtained  in  this  way,  as  the  fill 
will  settle  very  little.  When  back-filling  bridge  abutments  or  walls, 
surplus  water  should  be  pumped  out  before  the  backfill  is  made.  If 
this  is  not  done  the  fill  will  be  softened  to  such  an  extent  that  a 
fluid  pressure  will  be  created  that  far  exceeds  the  pressure  for  which 
the  abutment  or  wall  was  designed  and  serious  cracking  or  failure 
will  be  the  inevitable  result.  Care  should  always  be  taken  in  back- 
filling around  abutments  and  wings.  All  excavated  space  in  front 
of  wings  and  abutments  shall  be  filled  simultaneously  with  the  back- 
fill. If  this  is  not  done,  failure  is  liable  to  occur.  Do  not  permit  un- 
der any  conditions  the  puddling  of  back  fills  for  abutments  or  the 
dropping  of  earth  from  a  great  height  from  drag  line  buckets  or 
other  excavating  machinery. 

LAYING  PAVEMENT. 

50.  Concrete  Mixer.  Any  type  of  mixer  that  will  permit  mater- 
ials to  be  measured  accurately  and  will  mix  materials  to  a  uniform  con- 
sistency in  one  minute  of  time  shall  be  allowed.  Any  concrete  mixer 
that  will  not  turn  out  concrete  of  uniform  consistency  and  of  approxi- 
mately one  inch  slump  shall  not  be  permitted  on  the  work.  Many  mixer 
manufacturers  will  insist  that  their  machines  will  mix  concrete 
much  better  and  in  less  time  than  competing  mixers,  and  will  want 
the  advantage  of  mixing  materials  less  than  the  one  minute  stipu- 
lated in  the  specifications.  In  no  case  shall  preference  be  granted. 
51.  Timing  Devices.  All  mixers  on  pavement  construction  shall  be 
equipped  with  a  mechanical  timing  device  which  shall  warn  the  mixer 
operator  when  all  materials  in  the  drum  have  been  mixed  for  one  full 
minute.  If  the  timing  device  is  out  of  order  a  reasonable  time  should 
be  allowed  the  contractor  for  securing  repairs  but  in  no  case  shall  he 
be  allowed  more  than  72  hours  unless  he  shows  sufficient  reason  to 
justify  further  consideration  such  as  delay  in  the  delivery  of  the  repair 
parts. 

All  materials,  including  the  water,  for  each  batch  of  concrete  shall 
be  mixed  at  least  one  minute  while  the  drum  of  the  mixer  revolves  at 


26 

the  speed  for  which  it  was  designed.  In  a  few  instances  contractors 
will  persist  in  discharging  the  mixer  5  to  10  seconds  in  advance  of  the 
one  minute  time  specified.  This  practice  will  not  be  tolerated. 

52.  Charging  Mixer.    Inasmuch  as  the  specifications  will  not  per- 
mit material  to  be  dumped  on  the  subgrade,  paving  mixers  must  neces- 
sarily be  charged  by  means  of  batch  boxes  delivered  to  the  side  of  the 
mixer  by  industrial  railway  cars,  trucks,  or  wagons,  or  by  means  of 
dump  wagons  or  motor  driven  vehicles  which  may  be  arranged  to  dump 
materials  directly  into  the  skip  of  the  mixer. 

53.  Installation  of  Corrugated  Joints.     Corrugated  metal  joints 
shall  be  staked  securely  in  place  with  heavy  (No.  9)  wire  which  may 
be  left  in  the  concrete,  or  by  means  of  small  iron  stakes  that  may  be 
removed  after  the  concrete  has  been  deposited  and  partially  shaped 
to  the  cross  section  desired.     Frequent  inspection  of  corrugated  joints 
shall  be  made  during  the  finishing  operations  to  make  sure  they  have 
not  been  displaced.    Where  conditions  will  permit,  the  central  joint  may 
be  staked  into  place  in  advance  of  the  paving  mixer. 

The  corrugated  metal  strips  will  usually  be  purchased  in  10-foot 
lengths.  They  may  be  staked  in  place  with  the  ends  lapped  at  the  joints 
with  butt  joints,  or  with  open  joints  so  that  the  transverse  reinforcing 
bars  may  be  inserted  through  the  openings.  The  transverse  bars  may 
be  put  in  at  the  joints  or  at  intermediate  points  by  means  of  punching 
the  corrugated  metal  or  slotting  it  to  one-half  its  depth. 

54.  Tie  Bars.     The  deformed,  transverse   dowell    or    tie    bars 
should  be  anchored  into  place  before  the  concrete  is  deposited  or  they 
may  be  worked  into  place  after  the  concrete  in  the  pavement  has  been 
partially  shaped.     The  longitudinal  bars  may  be  held  in  place  by  iron 
stakes  or  chairs,  or  they  may  be  laid  on  the  subgrade  and  worked  up 
into  place  after  the  concrete  has  been  deposited.     In  the  latter  case, 
extreme  care  should  be  taken  to  see  that  the  concrete  thoroughly  sur- 
rounds the  bars  and  that  they  are  properly  located  when  the  pavement 
is  finished. 

55.  Subgrade  Templates.     A  template  cut  to  the  true  crown  of 
the  subgrade  shall  be  kept  in  advance  of  the  spreading  of  the  con- 
crete to  insure  that  the  subgrade  conforms  to  the  desired  cross  sec- 
tion.   When  a  paving  mixer  is  used  the  template  may  be  kept  between 
the  mixer  and  concrete,  or,  it  may  be  kept  ahead  of  the  placing  of  the 
longitudinal  steel  and  central  corrugated  metal  joint.     When  trucks 
are  used  for  delivering  batch  boxes  or  mixed  concrete,  the  template 
shall  be  set  in  place  frequently  to  insure  that  the  subgrade  has  the 
proper  cross  section  before  the  concrete  is  deposited  and  finished. 

The  template  shall  be  made  from  sound  wood  and  of  sufficient 
length  to  rest  upon  the  side  forms.  It  shall  be  cut  so  that  spikes  driven 
about  6  inches  apart  may  project  about  2  inches  from  the  lower  edge 
of  the  timber  and  so  that  the  heads  of  the  spikes  wrill  conform  to  the 
true  cross  section  of  the  subgrade  when  the  template  is  resting  on  the 
side  forms.  The  template  shall  be  moved  longitudinally  on  the  side 
forms  and  if  the  nail  heads  mar  the  subgrade,  sufficient  earth  shall  be 
removed  so  that  the  heads  will  just  touch  the  subgrade.  If  the  tern- 


pate  is  used  after  the  longitudinal  corrugated  joints  and  steel  have 
been  placed,  it  shall  be  notched  so  that  it  will  not  interfere  with  the 
metal  or  steel  bars.  If  a  mechanical  subgrader  is  used,  the  template 
will  not  have  to  be  used  as  frequently  as  when  the  subgrade  is  made 
by  hand.  A  template  should  always  be  on  the  job,  however,  and  used 
frequently  to  insure  getting  the  full  thickness  of  pavement  specified. 
Keep  in  mind  that  the  finished  pavement  shall  always  be  not  less  than 
the  cross  section  specified.  A  greater  thickness  is  not  objectionable 
but  is  not  wanted. 

56.  Header  Boards.     When  header  boards  are  installed  at  the 
noon  day  hour  or  at  the  completion  of  a  day's  work,  the  longitudinal 
bars  shall  pass  through  a  slot  in  the  header  board  a  distance  of  at 
least  2  feet  to  provide  for  the  proper  lapping  of  the  bars  at  the  joints. 
The  central  longitudinal  metal  joint  shall  butt  against  the  corrugated 
header  board. 

Header  boards  preferably  should  be  made  of  one-fourth  inch 
metal  corrugated  the  same  as  standard  corrugated  metal.  If  this  type 
of  header  is  too  expensive,  a  2  or  3-inch  timber  carefully  cut  to  the 
crown  of  the  road  and  faced  with  heavy  corrugated  metal  screwed  or 
tacked  into  place  may  be  used.  There  is  no  object  in  leaving  the  cor- 
rugated metal  in  place  at  construction  joints  so  it  may  be  fastened 
directly  to  the  wood  header.  Extreme  care  should  be  exercised  in 
setting  header  boards  at  the  noon  hour  and  upon  completion  of  the 
day's  work.  They  should  be  set  so  that  they  will  not  be  higher  than 
the  remainder  of  the  pavement.  Before  the  concrete  is  finally  finished 
at  the  header  board,  it  shall  be  checked  with  a  10-foot  straight  edge 
to  make  sure  that  it  conforms  to  the  true  cross  section  and  grade  of 
the  surface  of  the  pavement. 

57.  Noon   Day    Construction   Joints.     During  the   hot   summer 
months  when  there  is  more  than  one-half  hour's  delay  in  placing  con- 
crete, a  header  board  shall  be  set  the  same  as  when  the  work  is  com- 
pleted at  the  close  of  the  day.     If  this  is  not  done,  the  concrete  in  the 
tapered  joint  will  paritally  set  and  an  imperfect  bond  will  be  formed. 
The  tapered  joint  will  make  a  weak  plane  in  the  concrete  which  will 
likely  be  the  cause  for  a  "blow-up"  when  the  pavement  is  subjected 
to  excessive  temperature  stresses.    The  object  of  the  corrugated  metal 
or  surface   is   to  obtain  a  dovetailing  effect  between   the  two   slabs 
thereby   preventing   displacement   and   further   aiding   in   distributing 
concentrated  loads  that  may  be  applied  adjacent  to  the  construction 
joints. 

58.  Construction  Joints.     Construction     joints     should     be     in- 
stalled at  the  close  of  each  day's  work  and  during  the  hot  summer 
months  at  the  close  of  work  at  noon  provided  the  noon  period  is  thirty 
minutes   or  more.     All  construction  joints   shall   have   a   corrugated 
surface.    This  can  be  secured  either  by  laying  corrugated  metal  adja- 
cent to  the  header  board  or  by  securely  fastening  corrugated  metal 
to  the  header  board.     The  corrugated  metal  may  be  removed  when 
work  is  resumed.    All  construction  joints  should  be  carefully  checked 
with  a  10-foot  straight  edge  immediately  after  the  concrete  has  been 


28 

shaped  to  make  sure  that  they  do  not  vary  more  than  one-fourth  inch 
from  the  true  alignment  of  the  surface  of  the  road.  As  soon  as  the 
concrete  has  taken  its  initial  set  the  construction  joints  as  well  as  the 
edge  of  the  pavement  shall  be  neatly  edged  with  an  edging  tool  having 
a  one-half  inch  radius.  There  is  no  excuse  for  construction  joints 
being  built  high  or  low.  Any  joint  that  deviates  more  than  one- 
fourth  inch  from  a  10-foot  straight  edge  will  be  rejected  and  the  best 
time  to  correct  the  defect  is  before  the  concrete  takes  its  initial  set. 

59.  Late  Fall  Construction.     Late   fall  construction  should  al- 
ways be  protected  by  an  ample  covering  of  earth  or  straw  for  a  period 
of  at  least  five  days  after  the  concrete  has  been  finished  to  protect  it 
from  a  sudden  drop  in  temperature.    In  nearly  every  instance  the  con- 
tractor who  attempts   to   finish  a  pavement   in  November   will  have 
a  portion  of  his  work  injured  by  freezing.    Extreme  care  should  there- 
fore be  taken  to  see  that  the  road  is  amply  covered  so  that  the  proper 
quality  of  concrete  may  be  secured  and  the  contractor  saved  from  un- 
necessary expense.     If  the  contractor  attempts  to  do  much  late  fall 
construction  he  should  provide  plenty  of  canvas  or  felt  covered  frames, 
preferably  the  kind  that  arch  over  the  pavement  leaving  a  space  of  at 
least  two  feet  between  the  surface  of  the  pavement  and  the  canvas 
or  felt.    Oil  burners  or  salamanders  may  then  be  installed  beneath  the 
covering  to  generate  sufficient  heat  to  enable  the  pavement  to  harden 
so  that  the  road  may  be  covered  with  earth  or  straw  without  marring 
the  surface.     When  concrete  work  is  carried  on  during  very  cold  or 
freezing  weather  it  is  desirable  to  heat  the  water  before  it  goes  into 
the  mixture,  or  to  use  some  other  method  that  will  raise  the  tempera- 
ture of  the  mix  to  above  40°  F.  before  it  is  deposited  and  finished  in 
the  road.     Water  may  be  conveniently  heated  by  raising  the  pipe  line 
adjacent  to  the  mixer  for  a  distance  of  50  to  100  feet  and  building  a 
fire  beneath  it.     The  materials  in  the  drum  may  be  heated  by  special 
oil  burning  devices  that  are  now  on  the  market.     They  may  be  op- 
erated inside  of  the  mixer  drum  and  used  to  raise  the  temperature  of 
the  mix  several  degrees  during  the  period  of  mixing.     Concrete  can- 
not be  successfully  finished  if  its  temperature  is  below  40°  F.,  hence 
a  special  effort  should  be  made  to  have  the  material  at  a  temperature 
of  40°   or  higher  for  a  period  of  at  least  five  days  after  it  is  de- 
posited. 

60.  One-half  of  Pavement  Built  at  a  Time.     Where  the  stand- 
ard 18-foot  section  is  used  having  a  central  longitudinal  corrugated 
joint,  the  pavement  may  be  built  one-half  at  a  time.     If  this  method 
is  followed  a  9-foot  section  may  be  built  and  finished  with  the  finish- 
ing machine  the  same  as  a  standard  18-foot  pavement,  there  being, 
however,  no  longitudinal  reinforcing  bar  in  the  pavement  adjacent  to 
the  center  line.     The  transverse  bars  should  pass  through  the  forms 
at  the  center  points  or  at  the  joints,  and  after  the  forms  are  removed, 
the  bars  may  be  bent  to  one  side  at  an  angle  of  90°  provided  they  are 
bent  to  a  radius  of  at  least  four  inches.     When  the  second  half  of 
the  pavement  is  built  the  bars  shall  be  bent  back  into  place.    Extreme 
care  should  be  taken  to  see  that  the  bars  are  clean  and  that  the  bending 


does  not  break  the  old  concrete.  Where  the  road  is  built  in  halves,  the 
contractor  may  remove  the  central  corrugated  metal  strip  if  he  so  de- 
sires. There  is  no  object  in  the  metal  remaining  in  place  as  the  corru- 
gated surface  in  the  concrete  and  the  transverse  reinforcing  bars  form 
the  interlocking  joint  which  is  needed  for  transferring  loads  from  one 
side  of  the  joint  to  the  other.  The  last  half  of  the  pavement  should 
be  finished  with  a  specially  designed  finishing  machine  that  will  operate 
on  the  finished  pavement  and  one  side  form.  When  the  pavement 
is  constructed  in  two  9-foot  strips,  the  central  joint  shall  be  edged 
with  an  edging  tool  having  a  radius  of  one-half  inch. 

61.  Side  Forms  for  Pavements.     Pressed  steel   forms  shall  be 
used  for  all  pavement  construction.     They  shall  be  set  true  to  line  and 
grade  and  staked  in  such  a  manner  that  they  will  not  deviate  more  than 
one-fourth  inch  from  a  10-foot  straight  edge  after  the  material  has 
been  deposited  and  finished.     It  will  be  necessary,  therefore,  that  ex- 
treme care  be  used  in  securing  a  uniform,  well  compacted  subgrade, 
immediately  beneath  the  side  forms.     If  the  earth  will  not  support 
the  side  forms,  stakes  may  be  driven  beneath  the  forms  at  frequent 
intervals  to  strengthen  the  supporting  power  of  the  earth.     All  steel 
forms  shall  be  oiled  after  each  day's  use.     The  standard  10-foot  steel 
forms  should  be  used  for  all  curves  having  a  radius  of  200  feet  or 
more.    If  the  radius  is  less  than  200  feet,  better  results  will  ordinarily 
be  obtained  by  using  2x8  wood  forms  around  the  curve,  as  the  wood 
may  be  sprung  and  staked  and  made  to  conform  more  nearly  to  the 
curve  desired.    Where  wood  forms  are  used,  they  should  be  oiled  to 
prevent  the  concrete  from  adhering  to  them.     When  the  alignment 
of  a  10-foot  steel  section  deviates  more  than  one-fourth  inch  from  a 
10-foot  straight  edge,  it  should  be  rejected  and  not  used  in  the  work 
until  it  is  straightened.     Bent  or  battered   forms   shall   be   rejected. 
Resident  engineers  and  inspectors  should   frequently  check  with  the 
eye  the  vertical  and  horizontal  alignment  of  the  side  forms,  both  be- 
fore and  after  the  concrete  has  been  deposited.     Kinks  and  unneces- 
sary waves  and  all  irregularities  shall  be  immediately  corrected. 

62.  Proportioning   Aggregates   and   Cement.     Contractors    shall 
provide  a  means  on  the  job  for  proportioning  aggregates.    Two  boxes, 
one  holding  one  cubic  foot  and  one  holding  0.95  of  a  cubic  foot  shall 
be  provided  for  measuring  mixed  concrete  and  aggregates.     Cement, 
unless  delivered  in  bulk,  shall  be  measured  in  sacks.     The  theorectical 
amount  of  cement  needed  for  a  given  section  of  road  shall  be  de- 
termined by  mixing  with  water,  until  the  desired  consistency  is  se- 
cured, one  bag  of  cement  with  the  fine  and  coarse  aggregates  in  the 
proportions  specified  for  the  class  of  work  being  done.     The  mixed 
concrete  shall  then  be  tamped  in  the  one  cubic   foot  box  and  thus 
measured  to  determine  definitely  the  exact  number  of  cubic  feet  of 
mixed  concrete  that  may  be  obtained  from  one  bag  of  cement:  e.  g., 
the  cement  for  Class  X  concrete   (proportions  1:2:3^)   shall  be  de- 
termined by  mixing  one  bag  of  cement  with  two  accurately  measured 
boxes  of  sand  and  %y2  boxes  of  coarse  aggregate  with  sufficient  water 
to  secure  the  desired  consistency.     The  box  used  for  proportioning 


30 

aggregates  as  specified  in  the  preceding  sentence  shall  have  a  capacity 
of  0.95  of  a  cubic  foot.  The  mixed  concrete  shall  then  be  tamped  and 
measured  in  a  box  having  a  capacity  of  one  cubic  foot.  Several  such 
tests  shall  be  made  so  as  to  eliminate  slight  variations  in  aggregates. 
Whenever  there  is  a  radical  change  in  the  characteristics  of  aggregates, 
a  new  series  of  tests  shall  be  made  to  determine  the  theoretical  amount 
of  cement  required. 

This  method  will  enable  you  to  determine  definitely  the  amount  of 
cement  in  bags  needed  for  one  cubic  yard  of  concrete  or  100  feet  of 
pavement  using  the  materials  available.  After  the  concreting  is  be- 
gun and  occasionally  as  the  work  progresses,  the  material  for  one 
batch  shall  be  carefully  measured  (using  the  0.95  cubic  foot  box)  so 
that  you,  as  well  as  the  men  handling  the  materials,  may  become 
familiar  with  the  proper  proportions.  When  the  work  is  first  begun, 
all  batches  shall  be  very  carefully  measured  and  the  subgrade  care- 
fully shaped  so  that  you  can  check  the  exact  number  of  sacks  of  ce- 
ment required  for  each  25  or  100  feet  of  road.  If  the  pavement  is 
built  exactly  according  to  cross  section  and  the  proportions  accurately 
measured,  you  should  check  closely  the  amount  of  cement  required  as 
determined  by  the  use  of  the  one  cubic  foot  box.  At  the  end  of  each 
100  feet,  and  at  the  end  of  a  day's  run,  the  sacks  shall  be  counted  and 
a  record  made  of  the  amount  of  cement  used  in  each  100  feet  of  pave- 
ment and  the  total  used  during  the  day.  All  of  this  information  shall 
be  shown  in  your  memorandum  record  book  together  with  the  exact 
station  numbers. 

The  following  table  of  quantities  for  a  16  and  18  foot  concrete 
pavement  will  aid  in  determining  the  materials  needed  for  a  given 
section  of  road. 

MATERIALS   NEEDED   FOR  A    16-FOOT   PAVEMENT    HAVING   A   UNIFORM 
THICKNESS  OF  7  INCHES. 


£5  Co  c3  <^  C  ^  *•*  S  ^   r^  x    Q 

u         £  56  8  #  ^ 

100     feet..       55.65          16.64  29.22  34.57  60.00  333.33  52-.00 

1     mile 2,938.32        878.59        1,542.82        1,825.30        3,168.00        17,599.82        2,745.60 

1    sq.   yd..  .313  .094  .164  .194  .338  1.875  .293 

MATERIALS  NEEDED  FOR  AN  18-FOOT  PAVEMENT  HAVING  A  UNIFORM 
THICKNESS  OF  7   INCHES, 

100     feet.  .       62.61          18.72-  32.87  38.88  60.00  333.33  52.00 

1     mile..  .  .3,305.81        988.42        1,735.54        2,052.86        3,168.00        17,599.82        2,745.60 
1    sq.    yd..  .313  .094  .164  .194  .300  1.667  .260 

Note. — Assumptions: — 1  bbl.  of  cement  =  3.8  cu.  ft.  Voids  =  45%.  Excess 
of  agg.  =  7%.  Length  of  %"  o  bars  20'.  1  cu.  yd.  requires  1.61  bbls.  cement — 
0.45  cu.  yds.  Sand — 0.79  cu,  yds.  Stone  for  1-2-3 ^  mixture. 

63.     Combination  Truck  and  Industrial  Railroad  Delivery.     Batch 
boxes  may  be  delivered  to  a  paving  mixer  by  means   of   industrial 


31 

cars  on  tracks  at  the  side  of  the  road  very  economically.  This  method 
permits  the  subgrade  to  remain  in  perfect  condition  until  the  concrete 
has  been  placed.  In  a  few  instances  a  combination  of  truck  and  in- 
dustrial delivery  of  material  has  been  used  to  advantage.  Where 


Fig.  5.  One  and  one-half  ton  pneumatic  tired  truck  delivering  mixed 
concrete  from  central  plant  to  road. 


Fig.  6.  Aggregate  stored  on  top  of  a  tunnel  permits  large  storage 
of  material  and  easy  method  of  filling  batch  boxes  on  industrial  railroad 
equipment. 

the  road  to  be  improved  extends  from  the  material  yard  it  is  often 
possible  to  build  the  first  one  or  two  miles  by  the  use  of  a  short 
industrial  track.  The  subsequent  mileage  can  be  built  by  trucking 
the  material  over  the  improved  road  which  is  at  least  30  days  old, 
then  transferring  the  batch  boxes  to  industrial  cars  that  operate  on 


the  shoulder.  This  method  of  hauling  takes  advantage  of  industrial 
delivery  to  the  mixer  and  truck  haul  on  the  improved  road  that  has 
obtained  its  full  strength.  The  transfer  of  batch  boxes  from  trucks 
to  industrial  cars  can  usually  be  made  at  a  very  nominal  expense. 


Pig.  7.  Concrete  pavement  cured  by  ponding  method.     Note  tunnel 
and  material  yard  and  cement  storage  bins  in  background. 


Fig.  8.  Material  plant  for  central  proportioning  batch  boxes  for  in- 
dustrial railroad  delivery. 

64.  Team  Delivery  to  Mixer.  On  roads  that  have  sufficient 
right-of-way  to  provide  a  reasonably  good  earth  road  on  either  side 
of  the  pavement,  batch  boxes  of  material  may  be  delivered  direct 


33 

to  the  mixer  by  team  haul.  A  derrick  on  the  mixer,  or  independent 
of  the  mixer,  may  be  used  to  lift  the  batch  boxes  from  the  wagons 
and  discharge  them  into  the  skip  of  the  mixer.  This  method  fre- 
quently requires  a  temporary  bridge  over  the  pavement  so  that  the 
teams  may  cross  the  newly  laid  pavement  and  return  on  the  opposite 
side  of  the  road.  Team  delivery  usually  proves  economical  on  short 
hauls. 


Fig.  9.  Transfer  station  for  material  boxes  from  trucks  to  industrial 
cars.  Industrial  cars  deliver  materials  to  paving  mixer  about  one  mile 
ahead. 

65.  Proportioning  Materials  in  Batch  Boxes.  When  Batch  Boxes 
are  used  to  deliver  material  to  the  mixer,  the  sand  and  coarse  aggre- 
gate should  be  measured  preferably  by  means  of  separate  compart- 
ments in  the  batch  box.  However,  the  sand  and  coarse  aggregate 
may  be  dumped  into  the  same  compartment  provided  care  is  taken 
to  see  that  each  batch  box  is  filled  to  the  required  height  with  ag- 
gregate, or  filled  from  hoppers  that  will  measure  accurately  the  ma- 
terials. It  is  desirable  that  batch  boxes  contain  a  separate  compart- 
ment for  cement  although  this  is  not  necessary  if  the  batches  are 
used  within  a  few  hours  after  they  are  filled  and  are  not  exposed  to 
rain.  Where  the  aggregate  and  cement  are  dumped  into  one  com- 
partment at  the  material  yard,  a  plant  inspector  to  check  all  batches 
shall  be  provided  in  addition  to  the  inspector  out  on  the  road  where 
the  pavement  is  being  built.  If  the  cement  is  delivered  to  the  paving 
mixer  by  placing  a  given  number  of  sacks  on  top  of  each  batch  box, 
and  the  sacks  emptied  when  the  batch  reaches  the  paving  mixer,  ordi- 
narily no  plant  inspector  is  required.  In  this  instance  the  inspector 
at  the  paving  mixer  should  examine  carefully  the  batch  boxes  when 
delivered  to  make  sure  that  all  have  been  filled  with  aggregate  to 
the  proper  height  and  that  the  proper  number  of  sacks  is  on  each 
batch.  Cement  delivered  in  sacks  on  top  of  the  batch  boxes  can 
.usually  be  saved  in  case  of  a  wreck  on  the  delivery  system.  It  will 


34 

also  insure  the  proper  amount   for  each  batch  as  well  as  protect  it 
from  wind  and  from  moisture  in  the  aggregate. 

CEMENT. 

66.  Protecting  Cement  in  Transit  to  Mixer.     If  the  cement  is 
dumped  on  top  of  the  aggregate  .in  the  batch  boxes  at  the  material  yard 
some  method  of  covering  each  batch  shall  be  provided  so  as  to  protect 
it  from  rain  and  wind  while  in  transit.    There  is  no  objection  to  allow- 
ing cement  to  come  in  contact  with  the  wet  aggregate  for  about  one 
hour.     There  is,  however,  serious  objection  to  allowing  it  to  lie  on 
top  or  between  the  sand  and  coarse  aggregate  more  than  an  hour,  as 
the  cement  will  frequently  cake  and  lose  a  portion  of  its  value. 

67.  Bulk  Cement.     Bulk  cement  may  be  used  provided  suitable 
devices  are  installed  at  the  storage  plant  to  accurately  weigh  or  measure 
the  amount  of  cement  in  each  batch  of  material.    A  means  of  weighing 
the  required  amount  of  cement  is  preferable  to  a  measuring  method, 
although  measuring  will  be  satisfactory  if  a  device  is  provided  that  will 
cause  the  material  to  be  disturbed  uniformly  as  it  enters  the  measuring 
hopper  so  that  the  same  amount  in  bulk  will  be  provided  in  each  batch. 
The  measuring  hopper  shall  also  be  open  when  it  is  filled  so  that  each 
batch  may  be  carefully  examined  to  see  that  it  contains  the  required 
amount  of  cement.     Bulk  cement  may  be  shipped  in  open  top  gondola 
cars  and  unloaded  by  means  of  a  clam  shell,  but  in  such  cases  each 
car  shall  be  provided  with  a  suitable  canvas  covering  to  protect  it  from 
the  weather  during  transit.     Each  car  in  this  case  shall  be  examined 
upon  delivery  to  ascertain  the  amount  of  cement  damaged  or  cement 
lost  in  transit.     Any  cement  lost  in  this  manner  will  be  charged  to 
the  contractor  and  he  will  have  to  make  proper  adjustments  with  the 
cement  company  or  shipper.     Railroad  weights  on  bulk  delivery  of  ce- 
ment are  always  subject  to  considerable  error.    Accurate  record,  there- 
fore, shall  be  kept  of  all  batches  used  of  the  bulk  cement  and  this 
record  used  as  a  check  on  the  total  bulk  cement  delivered.    When  bulk 
cement  is  delivered  in  box  cars  it  may  be  unloaded  by  means  of  shovel- 
ing, drag  lines  or  air  suction.     In  any  case,  care  shall  be  used  to  see 
that  no  surplus  material  is  wasted  by  being  blown  away. 

68.  Cement  in  Sacks.     When  the   State  purchases  cement  the 
sacks  are  charged  to  the  contractor.     The  contractor  is  therefore  re- 
sponsible for  the  care  of  the  sacks  and  for  the  credit  which  he  receives 
on  them  when  they  are  returned  to  the  cement  companies.     Cement 
companies  usually  tack  a  card  on  the  inside  of  the  car  showing  the 
amount  of  cement  contained  in  the  car  according  to  the  mill  count. 
In  case  the  contents  check  short  of  the  amount  shown  on  the  card  or 
bill  of  lading,  this  card  shall  be  sent  in  with  your  complete  report  to 
the  district  engineer. 

Immediately  upon  receipt  of  a  car  of  cement  the  car  number,  in- 
itials, and  seal  number  shall  be  obtained.  The  seal  number  is  very  im- 
portant, as  in  case  of  damage  or  shortage  it  is  necessary  to  show  that 
the  original  seal  number  was  on  the  car  when  it  was  delivered.  As  soon 


35 

as  the  seal  is  broken  the  cement  becomes  the  property  of  the  contractor 
and  he  is  then  held  responsible  for  its  care  and  use.  Before  any  ce- 
ment is  removed  from  the  car  all  cement  sacks  shall  be  counted  if  the 
material  is  piled  in  such  a  way  as  to  permit  this ;  otherwise  a  careful 
check  shall  be  made  on  the  number  of  sacks  in  the  car  as  the  material 
is  unloaded. 

69.  Damaged  Cement.     If  there  is  any  damaged  cement  a  very 
careful  record  shall  be  made  of  the  number  of  sacks  and  a  description 
made  of  the  cause  of  damage.     When  there  is  any  great  amount  of 
defective  material  in  the  car  it  is  well  to  get  into  communication  with 
the  railroad  agent  and  bring  the  matter  to  his  attention  and  get  his  no- 
tation on  the  freight  bill.    A  careful  check  should  also  be  made  of  the 
damaged  sacks  that  are  unusable  at  the  time  the  cement  is  unloaded. 
If  there  is  a  large  number  of  damaged  sacks,,  the  bill  with  the  nota- 
tion thereon  shall  be  forwarded  promptly  to  the  district  engineer  with 
a  complete  explanation  of  the  shortage  or  the  damaged  material  so 
that  he  may  file  claim  with  the  cement  company  without  delay.     In 
all  cases  the  unusable  sacks  shall  be  found  in  separate  bundles  when 
returned  to  the  cement  company  so  that  proper  credit  can  be  given  to 
the  contractor. 

70.  Cement  Records  and  Reports.     Practically  all  of  the  above 
information  should  be  obtained  by  a  representative  of  the  contractor. 
However,  if  you  have  a  material  yard  inspector  he  should  secure  all 
of  this  information  first  hand.    If  there  is  but  one  inspector  on  the  job 
and  you  do  not  have  time  to  check  any  of  the  materials  as  they  are 
received  at  destination  you  should  make  a   special   effort   to   secure 
all  the  information  from  the  contractor  at  the  close  of  each  day.     Ce- 
ment shall  be  reported  to  the  district  office  on  regular  cards.     These 
cards  shall  be  made  only  from  actual  knowledge  of  the  receipt  of  the 
cars  and  any  discrepancies  in  the  amount  of  cement  in  the  car  from  the 
amount  shown  on  the  testing  engineer's  card  shall  be  noted  on  the 
report.    A  very  careful  record  of  cement  shipments  shall  be  kept  and 
the  resident  engineer  shall  keep  himself  informed  as  to  the  actual  dis- 
position of  every  car  of  cement  reported  to  his  job. 

71.  Cleaning  Cement  Sacks.    When  the  cement  sacks  are  emptied 
into  batch  boxes  or  mixers,  caution  the  men  emptying  the  sacks  to  shake 
each  one  thoroughly.    Laborers  often  become  very  careless  in  the  hand- 
ling of  cement  sacks  and  frequently  leave  one  or  two  pounds  of  cement 
in  each  sack.    This,  in  some  cases,  may  be  intentional  as  the  contractor 
will  clean  the  sacks  with  a  cleaning  machine  and  thereby  obtain  con- 
siderable additional  cement.     With  the  ordinary  cleaning  machine  it 
is  possible  to  save  enough  cement  even  after  a  thorough  shaking  of 
the  sacks  to  pay  for  the  machine  in  one  or  two  season's  work.     Thor- 
ough cleaning  of  the  sacks  by  means  of  machines  should  be  encouraged 
as  it  will  enable  the  contractor  to  obtain  some  additional  cement  and 
reduce  the  cost  of  return  freight  on  empty  sacks. 

72.  Storing  Cement.    Contractors  should  arrange  to  store  a  por- 
tion of  their  cement  on  all  work  which  they  have  to  do.    It  is  practically 
impossible  to  depend  upon  regular  cement  shipments  due  to  delays  at 


30 

the  cement  plant  and  to  railroad  transportation.  In  general,  a  con- 
tractor should  store  approximately  25  per  cent  of  his  requirements  to 
prevent  delays.  Cement  ordinarily  can  be  most  economically  stored  in 
especially  built  warehouses,  adjacent  to  the  railroad  siding.  These 
warehouses  may  be  built  by  placing  cross  stringers  or  sleepers  directly 
upon  the  earth  or  upon  cinders  and  laying  two-inch  planking  longitud- 
inally. The  flooring  should  be  covered  with  tar  paper  or  a  good  thick- 
ness of  dry  straw  to  prevent  circulation  of  air.  The  floor  should  be 
independent  of  the  side  walls  so  that  irregular  settlement  will  not  wreck 
the  warehouse.  Cement  buildings  are  usually  14  to  16  feet  in  width,  12 
to  16  feet  in  height  and  from  80  to  100  feet  in  length. 

In  storing  cement  the  sacks  should  be  packed  as  closely  together 
as  possible  leaving  a  space  of  about  one  foot  between  the  sacks  and 
the  side  walls.  If  the  cement  is  to  remain  in  storage  throughout  the 
winter  it  is  advisable  to  pack  the  space  between  the  cement  and  side 
walls  with  dry  straw.  Cement  should  be  covered  with  tar  paper,  canvas 
or  straw  so  as  to  prevent  circulation  of  air.  If  the  sacks  are  stacked 
carefully  you  can  allow  about  1.1  cubic  feet  for  each  sack.  When  stor- 
age cement  is  being  used  it  shall  be  examined  very  carefully.  In  every 
case  frequent  samples  shall  be  taken  and  tested  before  it  is  used  in  the 
work.  If  it  contains  lumps  they  shall  be  screened  out  before  the  cement 
is  used. 

73.  Cement  Tests.     For  each  car  of  cement  received  on  the  job 
you  should  receive  a  card  from  the  testing  engineer  showing  the  con- 
tents of  the  car  and  whether  or  not  it  is  acceptable.     In  case  you  re- 
ceive a  car  of  rejected  cement,  report  it  immediately  to  the  testing- 
engineer  and  await  instructions  for  the  disposal  of  the  car.    If  the  con- 
tractor is  authorized  to  secure  a  small  amount  of  cement  locally,  it 
should  be  tested  and  you  shall  select  a  small  sample  in  accordance  with 
established  practice  and  forward  to  the  testing  engineer  at  the  Spring- 
field office  that  a  record  may  be  kept  of  its  quality. 

74.  Borrozving  or  Buying  Cement.     If,  for  reasons  beyond  the 
control  of  the  contractor,  cement  does  not  arrive  when  it  is  needed  and 
he  has  ordered  it  a  reasonable  time  in  advance,  he  may  be  authorized 
to  borrow  or  purchase  some  cement  locally.    Should  this  situation  arise, 
communicate  with  your  district  engineer  at  once  so  that  he  may  issue 
proper  authorizations. 

MATERIALS. 

75.  Material  Tests.    All  aggregates  will  generally  be  tested  at  the 
shipping  point  and  you  should  receive  a  card  from  the  testing  engineer 
showing  that  the  material  is  acceptable.     In  case  you  should  receive  a 
car  of  material  which  it  is  evident  does  not  comply  with  the  specifica- 
tions, you  shall  delay  using  it  until  you  have  submitted  a  sample  to  the 
testing  engineer  and  have  received  his  report.     In  a  few  instances  ma- 
terial received  may  be  entirely  satisfactory  but  may  become  mixed  with 
dirt  or  other  foreign  material  on  the  job  so  that  it  is  not  fit  for  use 
in  concrete  construction.     Such  material  should  be  rejected  by  you  or 


37 

at  least  reported  to  the  district  engineer  and  his  decision  secured  before 
the  material  is  used  in  the  work. 

76.  Storing  Material.    Contractors  are  compelled  to  store  consid- 
erable aggregate  to  insure  constant  and  uniform  operation  of  the  plant. 
When  the  material  is  unloaded  by  clam  shells  it  is  frequently  stored  in 
large  piles.     1  he  clam  shell  operator  will  ordinarily  dump  the  material 
in  the  center  of  the  storage  pile.    This  will  soon  result  in  a  very  large 
percentage  of  the  coarse  material  rolling  down  the  sides  leaving  a  core 
that  contains  an  excess  of  fine  material.     When  the  aggregate  is  re- 
handled  for  use  it  will  not  be  properly  graded  and  the  best  results  can- 
not be  secured.     The  separation  of  the  materials  may  be  very  largely 
avoided  by  building  up  the  storage  pile  in  horizontal  layers  instead  of 
dumping  all  the  material  at  the  one  central  point. 

CENTRAL  MIXING  PLANTS. 

77.  Many   advantages   are   claimed    for   central   mixing   plants. 
The  chief  advantage  is  perhaps  the  centralization  of  operations  which 
permits   more   careful   and   intense   supervision.      Also,   the   ordinary 
stationary  mixer  may  be  used  which  will  permit  a  large  volume  of 
concrete  to  be  turned  out  at  less  expense  than  with  a  standard  paver. 
It  is  frequently  much  easier  to  obtain  a  satisfactory  supply  of  water 
for  a  central  plant  than  for  a  field  mixer.     The  single  pipe  line  on 
the  road  is  not  overburdened  by  supplying  water  for  use  in  the  paver 
in  addition  to  the  use  for  curing  purposes.     The  central  mixers  fre- 
quently are  of   such   size  that  the  materials   may  actually  be  mixed 
more  than  one  minute  and  still  supply  all  the  concrete  that  it  is  pos- 
sible to  haul  and  finish  during  the  day.     There  is  some  advantage  in 
the  extra  time  of  mixing,  as  it  will  insure  a  better  quality  of  con- 
crete and  a  more  workable  mix  both  of  which  are  an  advantage  to 
the  contractor.     A  central  plant  also  gives  the  contractor  an  oppor- 
tunity to  work  out  many  labor  saving  devices  thereby  enabling  him 
to  mix  concrete  at  a  minimum  cost. 

78.  Hauling  Mixed  Concrete.     On  many  sections  of  road  work 
concrete  may  be  mixed  at  a  central  plant  and  then  delivered  to  the 
road  by  means  of  trucks.     Specifications  allow  a  period  of  40  min- 
utes from  the  time  the  concrete  is  mixed  until  it  is  deposited  in  the 
road.     This  time  is  stipulated  to  prevent  a  partial  set  of  the  concrete 
before  it  is  deposited  in  the  work.     Experience  has  shown  that  where 
a  contractor  attempts  to  haul  material  a  distance  which  requires  more 
than  40  minutes  of  time  he  is  not  doing  his  work  economically.     Dur- 
ing the  hot  summer  months   40  minutes   is  usually  longer  than  the 
contractor   should   count   on  to   haul   mixed  concrete.     Early   in  the 
spring  or  late  in  the  fall  there  would  be  no  objection  to  holding  the 
concrete  twice  the  time  stipulated.     In  general,  the  engineer  should 
not  concern  himself  with  the  time  that  mixed  concrete  has  been  held, 
but  should  see  that  the  concrete  when  delivered  to  the  road  is  properly 
spread  and  finished  in  the  pavement.    .When  mixed  concrete  cannot 
be  satisfactorily  finished  it  has  undoubtedly  been  held  in  transit  too 
long  and  should  be  rejected. 


38 

Mixed  concrete  will  ordinarily  be  delivered  in  one  to  two-ton 
trucks  having  pneumatic  tires.  The  pneumatic  tires  facilitate  speed 
and  prevent  serious  injury  to  the  subgrade,  and  are  therefore  more 
desirable  for  hauling  mixed  concrete. 


Fig.  10.  One-ton  truck  loaded  with  mixed  concrete  being  turned  on 
subgrade. 


Fig.  11.  Central  Mixing  Plant. 

79.  Consistency  of  Mixed  Concrete.  When  mixed  concrete  is 
to  be  hauled  any  distance  extreme  care  should  be  taken  to  see  that 
the  consistency  of  the  concrete  is  uniformly  stiff.  The  aggregate  in 
sloppy  concrete  will  segregate  while  in  transit  and  will  be  not  only 
unsatisfactory  for  use  in  pavements  but  extremely  difficult  to  dump 
from  an  ordinary  truck  bodv.  After  the  mixed  concrete  is  delivered 


39 

at  destination  the  truck  load  should  have  but  a  small  film  of  water 
on  the  surface  and  when  the  material  is  dumped  should  show  a  uni- 
form consistency  and  mix.  Mixed  concrete  has  been  hauled  for  a 
distance  of  five  or  six  miles  over  ordinary  country  roads  even  in  the 
hottest  weather  without  injury  to  the  concrete. 

80.  Finishing  Mixed  Concrete.     Experience  has   shown  that  it 
requires  additional  labor  to  shape  and  finish  mixed  concrete  that  has 
been  hauled  for  some  distance.     In  no  case  should  retempering  of  the 
delivered  concrete  be  permitted.     If  extra  labor  cannot  finish  the  con- 
crete as  it  should  be,  it  shall  be  thrown  out  and  fresh  material  put 
in  its  place. 

FINISHING   CONCRETE   PAVEMENTS. 

81.  Finishing  Machine.     Some  form  of  mechanical  tamper  and 
finisher  is  required  to  finish  concrete  roads  in  accordance  with  speci- 
fications.    It  is  necessary,  therefore,  to  examine  very  carefully  the 
finishing  machine  that  is  being  used  to  see  that  the  templets  are  cut 
to  the  desired  crown  so  that  the  finished  pavement  will  have  the  re- 
quired cross  section.     It  is  also  necessary  to  watch  the  machine  fre- 
quently to  see  that  it  is  in  proper  adjustment  so  that  both  sides  of 
the  road  are  completed  alike.     Frequently  the  tension  on  one  side 
of  the  finishing  machine  is  weakened  resulting  in  a  very  small  vertical 
motion  and  non-uniform  results.     The  finishing  belt  shall  be  cleaned 
at  the  close  of  each  day's  work  and  kept  soft  by  means  of  soaking 
in  water  or  oil  so  that  it  is  pliable  at  all  times.     The  drip  pan  be- 
neath the  engine  shall  be  tight  to  prevent  oil  from  dripping  on  the 
newly  laid  concrete.     Machine  oil  on  green  concrete  usually  causes 
serious    disintegration.      The   purpose   of    a   finishing   machine   is   to 
strike  off  the  slight  amount  of  extra  concrete  that  is  deposited  in  the 
road  and  to  thoroughly  tamp  and  finish  it  to  the  desired  crown.     In 
most  instances  the  workmen  who  spread  the  concrete  do  not  get  it 
to  the  true  crown,  often  leaving  high  spots  for  the  finishing  machine 
to  pull  down,  or  in  other  words,  leave  a  large  percentage  of  their 
work  to  be  done  by  the  finishing  machine.     Where  the  machine  is 
required  to  push  ahead  a  large  surplus  of  concrete  it  is  sure  to  be 
injured,  and  further  will  leave  an  uneven  surface  in  the  finished  pave- 
ment.   The  machine  should  normally  push  two  or  three  inches  of  con- 
crete ahead  of  the  strike-off  templet  to  insure  uniform  results.     If  the 
machine  is  required  to  push  more  than  this  amount  of  concrete  it  will 
naturally  drag  more  of  the  concrete  ahead  than  it  should  and  for  this 
reason  leave  low  spots  or  depressions  in  the  finished  pavement.    If  the 
proper  amount  of  concrete  is  deposited  between  the  forms  the  machine 
will  usually  finish  the  pavement  true  to  the  top  of  the  forms  and  will  not 
push  any  surplus  concrete  over  the  side.     If  the  templets  are  properly 
adjusted  they  will  usually  clean  the  forms  thereby  insuring  a  much 
more  uniform  and  even  surface. 


40 


82.  Checking  Finished  Surface.  After  the  machine  has  passed 
over  the  forms  two  or  three  times  the  finished  grade  of  the  forms 
should  be  checked  either  with  the  eye  or  by  the  use  of  a  10-foot 
straight  edge.  If  they  deviate  more  than  one-fourth  inch  from  the 
10-foot  straight  edge  they  have  probably  been  driven  into  the  ground 
by  overtamping  or  by  not  having  been  properly  supported.  If  settle- 
ment has  occurred,  the  forms  should  immediately  be  adjusted  to 
grade  and  additional  material  spread  upon  the  surface  of  the  road  be- 
fore the  final  finishing  and  belting.  This  is  absolutely  necessary  to 
insure  the  proper  finish  to  the  pavement. 


Fig.  12.  Porous  spots  in  concrete  surface  can  be  avoided  if  a  small 
amount  of  concrete  is  kept  in  advance  of  the  templet  when  the  finishing 
machine  is  moved  forward. 

83.  Overtamping  Surface.     Ordinarily  concrete  that  is  deposited 
on  the  road  can  be  finished  by  passing  the  machine  over  the  surface 
four  or  five  times.     In  many  instances  concrete  roads  are  overtamped. 
If  this  is  done  a  surplus  of  laitance  is  brought  to  the  surface  of  the 
road  and  the   side   forms   are   settled   and   usually   an   unsatisfactory 
alignment  and  surface  finish  are  the  result.    When  convenient,  accurate 
measurements   should  be  taken  at  given  points  on  the  finished  sub- 
grade  and  similar  measurements  taken  after  the  pavement  has  been 
finished  to  see  just  what  thickness  of  concrete  has  actually  been  se- 
cured.    Frequently  finishing  machines  settle  the  side  forms  as  much 
as  one-half  inch  and  you  will  get  a  corresponding  reduction  in  the 
finished  thickness  of  the  pavement. 

84.  Final  Finish.     The  final  belting  of 'a  pavement  can  be  done 
with  a  hand  belt  or  with  the  belt  on  the  finishing  machine.     Either 
will  give  a  desirable  finish,  if  used  just  prior  to  the  initial  set  of  the 
concrete.     The  final  belting  shall  ordinarily  be  done  from  50  to  100 
feet  behind  the  mixer.     When  500  to  800  feet  of  concrete  is  being  laid 
per  day  it  is  necessary  to  follow  the  finishing  machine  with  a  belt  oper- 
ated by  hand  as  the  ordinary  finishing  machine  is  not  designed  to  tamp 


41 

and  finish  a  greater  volume  of  work.  If  more  than  800  lineal  feet 
is  laid  per  day  it  is  necessary  to  have  at  least  two  finishing  machines 
on  the  job. 

85.  Hand  Roller  and  Belt.     A  belt  that  can  be  operated  by  hand 
as  well  as  a  small  hand  roller  and  a  hand  tamping  templet  shall  be  on 
each  job  at  all  times  so  that  they  can  be  put  into  operation  immediately 
upon  a  break  down  of  the  finishing  machine.     If  this  is  not  done  and 
a  break  down  occurs  it  may  often  be  necessary  to  remove  the  concrete 
— an  operation  which  would  entail  considerable  expense. 

86.  Finishing   Curves.     The  hand  tamping  templet,   roller   and 
belt  are  necessary  for  finishing  around  curves  having  a  radius  of  less 
than  200  feet.     On  the  maximum  superelevated  curves  the  finishing 
machine  causes  considerable  trouble  by  forcing  the  soft  concrete  to 
the  lower  side  of  the  pavement  thereby  giving  an  irregular  or  poor 
finish   in   the   surface   of   the   pavement.     The    free   use   of   a   hand 
tamper,   roller   and   belt   will   insure   a   much   better   surface   on   the 
superelevated  curves. 


Fig.  13.  Ten-foot   straight   edge   shows   up    a   depression    of   three- 
fourths  inch  in  the  finished  surface. 

87.  Use  of  lo-foot  Straight  Edge.  As  soon  as  the  concrete  road 
has  been  finished  it  shall  be  carefully  checked  for  high  and  low  spots. 
The  10-foot  straight  edge  will  enable  you  to  find  these  spots.  The 
concrete  surface  shall  be  carefully  checked  with  the  eye  as  well  as 
with  the  straight  edge  before  it  takes  its  initial  set  so  that  the  surface 
may  be  corrected  by  removing  or  adding  material.  If  a  given  spot  is 
found  to  be  low  or  high  it  shall  be  immediately  marked  by  scratching 
the  surface  after  which  it  should  be  called  to  the  attention  of  the 
superintendent  or  foreman  in  charge.  Do  not  wait  until  the  next  day 
when  the  concrete  has  taken  its  final  set  as  then  it  will  be  very  diffi- 
cult to  correct  the  surface.  In  case  a  high  or  low  spot  was  overlooked 
during  the  day's  work  it  shall  be  immediately  checked  the  following 


42 


morning  before  the  road  is  covered  with  earth  or  curing  material. 
If  the  surface  deviates  at  any  one  place  more  than  one-fourth  inch 
from  the  10- foot  straight  edge  it  shall  be  immediately  trimmed  off  and 
fresh  mortar  floated  into  the  surface  so  as  to  give  the  pavement  the 
desired  cross  section  and  finish.  There  is  no  excuse  for  a  pavement 
being  built  with  a  deviation  in  its  surface  of  more  than  one-fourth 
inch  from  a  10- foot  straight  edge.  Pavements  having  a  greater  de- 
viation will  not  be  accepted;  hence  the  surface  should  be  corrected 
before  the  concrete  takes  its  initial  set. 


Fig.  14. 
erosion. 


Slope-wall  construction  to  protect  road  from  excessive 


88.  Character  of  Finished  Pavement.    The  efficiency  of  the  engi- 
neer in  charge  as  well  as  that  of  the  contractor  is  generally  judged 
by  the  riding  qualities  of  the  finished  pavement.     A  road  may  be  100 
per  cent  perfect  in  all  of  its  other  qualifications  but  if  it  has  a  poor 
finish  the  work  is  condemned  by  the  traveling  public  and  the  engi- 
neer and  contractor  subjected  to  severe  criticism.     On  the  other  hand, 
the  qualities  of  a  pavement  may  not  be  up  to  standard  yet  if  it  has 
a  perfect  finish  the  work  will  have  the  appearance  of  having  been 
carefully  done  and  it  will  at  least  give  some  satisfaction  to  the  travel- 
ing public.    An  uneven  surface  is  not  only  unsatisfactory  to  the  pub- 
lic but  is  frequently  the  cause  of  the  destruction  of  the  pavement. 
Tests  have   shown  that  a  one- fourth  inch   deviation  in  the  surface 
will  impose  impact  loads  of  from  two  to  five  times  the  weight  of  the 
load. 

SPECIAL  SECTIONS. 

89.  Curb  and  Gutter  Sections.     Curb  and  gutter  sections  should 
be  used  on  practically  all  grades  that  are  4  per  cent  or  more,  on 
heavy  cut  sections  to  save  excavation,  and  on  long  slopes  where  the 
side  ditches  or  shoulders  are  subjected  to  erosion.     The  chief  pur- 


poses  of  the  curb  and  gutter  sections  are  to  carry  the  water  in  the 
gutter  or  upon  the  road  to  the  bottom  of  the  grade  where  it  may  be 
discharged  without  washing  the  road,  and  to  prevent  the  side  slopes 
from  sloughing  off  and  filling  the  ditches.  Where  the  curb  and  gut- 
ter is  carried  to  the  culvert  a  very  careful  plan  shall  be  worked  out 
to  dispose  of  the  water.  Curb  sections  may  be  built  monolithic  with 
the  pavement  or  separate  from  the  pavement  at  the  desire  of  the 
contractor.  In  general,  the  contractor  will  choose  to  build  the  pave- 
ment first  so  that  he  may  use  his  standard  finishing  machine.  If  this 
is  done,  the  tie*  rods  should  be  inserted  in  the  pavement  at  the  inter- 
vals specified  and  a  longitudinal  bar  placed  in  the  curb  and  gutter 
section  to  give  it  the  desired  supporting  strength.  If  proper  forms 
are  made  for  the  curb  and  gutter  it  can  be  built  very  rapidly  and  will 
conform  to  the  cross  section  details  shown  on  the  plans.  Consider- 
able hand  work  will  have  to  be  done  to  get  the  desired  finish.  There 
is  no  reason  why  it  should  not  be  finished  just  as  smoothly  as  the 
remainder  of  the  road.  Special  care  should  be  taken  to  see  that  the 
face  and  back  of  the  curbs  are  in  perfect  alignment  so  that  the  road 
will  present  the  desired  appearance.  The  back  of  the  curb  line  should 
be  edged  with  a  one-fourth  to  one-half  inch  edging  tool. 

90.  Curb  and  Glitter  Turnouts.  At  the  bottom  of  steep  slopes 
where  curb  and  gutter  sections  are  used  the  turnout  for  the  water  will 
ordinarily  be  constructed  at  the  junction  of  the  cut  and  fill  sections. 
However,  if  the  fill  is  on  a  steep  grade  it  would  be  advisable  to  con- 
tinue the  curb  or  gutter  section  to  the  culvert  or  to  some  point  where 
the  grade  has  flattened  to  such  an  extent  that  the  surface  water  may 


Pig.  15.  Curb  and  gutter  outlet  at  bottom  of  steep  grade. 

be  readily  conducted  down  the  side  of  the  embankment.  If  the  take- 
off gutter  is  built  too  far  up  on  the  hill  slope  the  surface  water  will 
accumulate  adjacent  to  the  pavement  on  the  filled  section  and  continue 
to  cause  excessive  maintenance.  Where  it  is  possible  to  continue 
the  curb  or  gutter  to  the  culvert  the  water  may  be  discharged  through 


44 

the  head  wall  if  an  apron  is  provided  in  the  bed  of  the  stream  just  be- 
neath the  opening  to  prevent  scouring.  In  a  few  instances  it  may  be 
taken  through  the  top  of  the  culvert  box,  although  in  general,  this 
should  be  discouraged  as  it  is  necessary  to  have  the  water  pass 
through  the  reinforcing  bars  or  some  other  grating  which  will  event- 
ually become  clogged  and  cause  serious  damage  on  account  of  over- 
flow. 


Fig.  16.  Gutter  section  on  steep  grade  and  through  a  heavy  cut. 


Fig.  17.  Curb  and  gutter  construction  on  steep  grades  and  through 
heavy  cuts. 

91.  Grate  Bars.  The  installation  of  sewer  pipe  and  grate  bars 
in  a  curb  or  gutter  line  should  be  discouraged  as  invariably  foreign 
material  will  collect  over  the  grate  and  the  sewer  will  fail  to  function 
at  a  time  when  it  is  most  needed. 


45 

92.  Gutter  Section.    When  a  semi-circular  shaped  gutter  is  built 
adjacent  to  the  edge  of  the  slab  the  earth  shall  be  carefully  shaped 
to  the  desired  cross  section.     A  form  board  shall  then  be  set  for  the 
outside  edge  of  the  gutter  section  and  the  concrete  poured  and  molded 
to  the  desired  shape  before  it  takes  its  initial  set.     In  any  case  where 
a  curb  or  semi-circular  gutter  is  used  to  conduct  water  it  shall  be 
turned  very  gradually  away  from  the  road  at  the  bottom  of  the  hill. 
Any  abrupt  turn  in  the  gutter  will  cause  the  water  to  overflow  and 
this  will  result  in  serious  erosion  on  the  shoulder  beyond  the  point 
where  the  gutter  turns  off. 

CURING. 

93.  Newly  laid  concrete  pavements   shall  be  kept  moist   for  a 
period  of  at  least  two  weeks.     Brick  pavements  with  a  cement  grout 
tiller  shall  be  kept  moist  for  at  least  10  days. 

94.  Ponding  Method  of  Curing.     The  surest,  and  possibly  the 
most  desirable  method  that  may  be  used  for  curing  pavements,  is  to 
pond  the  water  on  the  surface  of  the  road.     This  can  be  done  by 
building  dykes  along  the  edges  of  the  pavement  and  cross  dykes  at 
intervals  of  from  5  to  50  feet  to  prevent  water  from  flowing  down 
the  grades. 

95.  Use  of  Straw  for  Curing.     Some  soil  will  not  hold  water, 
hence  it  is  impossible  to  use  the  ponding  method  for  curing.     In  such 
cases  it  is  desirable  to  use  six  or  eight  inches  of  half  rotten  straw. 


Pig.  18.  Canvas  covering  on  newly  laid  concrete  pavement  to  pro- 
tect it  from  sun  and  wind.  Canvas  should  be  kept  wet  when  weather  is 
extremely  hot. 

The  partially  decayed  straw,  with  as  much  chaff  in  it  as  it  is  possible 
to  secure,  will  lie  close  to  the  pavement  and  hold  moisture  for  a  con- 
siderable time.  The  straw  covering  can  be  very  easily  advanced  as 
soon  as  the  surface  has  been  cured  the  desired  time.  If  straw  can  be 


46 

secured  at  a  reasonable  price  this  method  of  curing  will  probably  prove 
as  desirable  and  economical  as  any  method  that  could  be  followed. 

96.  Earth  Covering.  A  common  method  which  is  used  for  cur- 
ing is  that  of  covering  the  pavement  with  at  least  two  inches  of  loose 
earth  which  may  be  shoveled  from  the  sides  of  the  road  and  the 
material  kept  moist  by  frequent  sprinkling.  The  earth  preferably 
should  be  plowed  before  it  is  shoveled  on  to  the  pavement.  In  many 
cases  the  contractor  can  have  this  covering  done  on  the  unit  price 
basis  thereby  securing  more  desirable  and  economical  results.  The 
earth  covering  shall  be  sprinkled  frequently  to  keep  the  pavement  moist 
for  the  required  time.  In  all  cases  the  edges  of  the  pavement  shall  be 
banked  and  cured  the  same  as  the  surface. 


Fig.  19.  Canvas  covered  frames  used  to  cover  a  concrete  road  im- 
mediately behind  the  paving  mixer. 

97.  Protecting  Pavew,ent  by  Use  of  Frames  and  Canvas.  In 
every  case  concrete  pavements  shall  be  covered  by  10  o'clock  A.  M. 
on  the  day  after  the  work  has  been  finished.  During  the  hot  summer 
months  it  is  necessary  to  cover  the  pavement  and  keep  it  moist  just 
as  closely  behind  the  mixer  as  it  is  possible  to  work  without  marring 
the  surface  of  the  road.  Pavement  that  is  laid  during  these  months  shall 
be  protected  by  the  use  of  frames  covered  with  canvas  or  other  ma- 
terial that  will  keep  the  sun  and  wind  from  the  surface  of  the  roadway. 
Usually  100  feet  of  such  frames  is  sufficient  to  protect  the  soft  con- 
crete that  has  been  finished  and  to  prevent  it  from  hair  checking  or 
drying  out  too  rapidly.  Following  the  frames  the  canvas  may  be  laid 
directly  upon  the  surface.  In  no  case,  however,  should  canvas  be  laid 
on  the  surface  of  soft  concrete  as  it  will  mar  the  finish  and  make  it 
very  undesirable.  In  some  instances  the  contractor  may  arrange  for 
the  frames  to  be  fastened  to  wheels  that  run  on  the  side  forms.  Where 
this  is  done  the  frames  may  be  pulled  ahead  as  the  finishing  machine 
completes  its  work.  The  pavement  can  be  covered  with  straw  or 
earth  after  the  curing  frames  have  been  moved  forward. 


47 

98.  Experimental  Methods  of  Curing  Pavements.     There  are 
other  methods  that  are  being  used  to  some  extent  in  the  curing  of 
pavements,  although  they  have  not  as  yet  been  perfected  and  should  not 
be  used  unless  specific  instructions  have  been  received  from  the  Chief 
Highway  Engineer.     They  may  be  listed  as   follows : 

1.  An  oil  covering  of  60  to  90  per  cent  asphaltum  content  ap- 
plied hot  at  the  rate  of  one-third  gallon  per  square  yard.     The 
purpose  of  the  oil  is  to  prevent  evaporation  of  the  moisture  that 
is  in  the  concrete.     Tests   indicate   that  concrete  will  obtain  its 
full  strength  if  all  water  used  in  the  original  mix  is  retained. 

2.  A  blanket  of  one-eighth  to  three-sixteenths  of  an  inch  thick 
of  a  heavy  grade  of  asphalt  such  as  might  be  used  for  ordinary 
brick  filler  (35  to  60  penetration)  may  be  applied  when  the  sur- 
face of  the  concrete  is  moist  and  in  this  way  prevent  evaporation. 
After  the  curing  period,  the  asphalt  may  be  peeled  off  the  surface 
and  reused. 

3.  Calcium  chloride  in  a  very  rich  solution  sprinkled  on  the 
surface  of  the  pavement  as  soon  as  the  concrete  has  taken  its  final 
set  may  also  be  used  with  some  success.     This  material  has  an  af- 
finity for  drawing  moisture  from  the  air,,  hence  when  it  is  used 
on  the  surface  of  a  pavement,  the  pavement  is  kept  moist.     The 
objection  to  this  method  is  the  expense  and  the  possibility  of  the 
chloride  solution  being  washed  off  the  surface  by  a  heavy  rainfall. 
A  slight  covering  of  earth  (y2  to  1  inch)   in  connection  with  the 
use  of  calcium  chloride  is  desirable  as  it  assists  in  preventing  the 
material  from  being  washed  off. 

4.  The  road  surface  may  be  kept  moist  by  installing  a  pipe 
line  down  the  center  of  the  pavement  and  inserting  spraying  noz- 
zles at  intervals  of  from  15  to  25  feet.     In  a  few  instances  this 
method  of  curing  has  proved  satisfactory.     However,  in  general 
there  are  always  a  few  of  the  spraying  nozzles  that  will  get  out 
of  order  and  the  pressure  will  vary  between  the  high  and  low 
points  in  the  road  so  that  a  uniform  spray  cannot  be  maintained. 
Hence  the  road  will  not  be  uniformly  cured. 

The  cost  of  curing  for  any  of  the  methods  described  above  will 
vary  from  4  to  12  cents  per  square  yard  of  surface. 

99.  Fall  and  Spring  Curing.     During  the  early  spring  and  late 
fall  it  is  not  always  necessary  to  cure  the  pavement  by  the  use  of  some 
sort  of  covering  that  is  kept  moist.     Pavements  finished  during  the 
month  of  April  will  ordinarily  not  require  any  additional  moisture  or 
covering  to  protect  them  from  the  sun  and  wind.    However,  this  should 
be  watched  very  carefully  as  we  occasionally  have  hot  and  windy  days 
during  April  that  make  it  necessary  to  protect  the  pavement  at  least 
with  two  inches  of  earth.     From  the  first  of  May  until  the  first  of 
October  the  pavement  should  be  covered  and  kept  moist  to  insure 
proper  curing.     During  October  and  November  it  is  not  usually  neces- 
sary to  add  water  for  curing  purposes  although  it  is  always  advisable  to 
cover  the  pavement  with  at  least  two  inches  of  earth  or  six  or  eight 
inches  of  straw  to  protect  the  surface  from  frost  and  freezing. 


48 

100.  Protecting  Surface  in  Freezing  Weather,     in  no  case  shall 
canvas  be  laid  directly  upon  concrete  before  it  obtains  a  set  sufficient 
to   prevent   the   canvas    from   marring   the    surface.      In   case    of    an 
emergency  where  the  road  must  be  covered  to  protect  it  from  freezing, 
dry  straw  may  be  scattered  over  the  surface  of  the  pavement  to  a 
sufficient  depth  to  prevent  frost  or  freezing.     In  general,  however,  the 
surface  should  be  dried  out  by  means  of  artificial  heat  so  that  it  will 
not  be  marred  by  the  straw  or  earth  covering. 

101.  Preventing  Concrete  from  Freezing.     It  is  possible  to  pre- 
vent concrete  from  freezing  by  adding  a  small  percentage  of  calcium 
chloride  to  the  mix.     Calcium  chloride  may  be  purchased  in  the  pow- 
dered form  and  added  to  the  mixture  in  the  ratio  of  two  pounds  to 
each  one  hundred  pounds  of  cement  used.    This  will  prevent  concrete 
from  freezing  to  a  temperature  of  about  15°  F.     It  is  not  advisable 
to  use  more  than  this  ratio  as  it  will  hasten  the  setting  process  to 
such  an  extent  that  it  will  be  impossible  for  the  workmen  to  finish  the 
pavement.     Calcium  chloride  does  not  seem  to  injure  the  concrete  mix 
in  any  way,  but  it  causes  the  concrete  to  set  so  quickly  that  it  attains 
a  strength  in  five  or  six  days  almost  equal  to  that  of  ordinary  concrete 
after  a  period  of  thirty  days.  There  is  objection,  however,  to  the  use  of 
calcium  chloride  in  connection  with  reinforced  concrete  as  it  will  at- 
tack and  destroy  the  reinforcing  steel.   Ordinary  salt  is  used  frequently 
in  concrete  to  lower  the  freezing  temperature.    This  should  not  be  used 
as  it  is  possible  to  lower  the  temperature  but  two  or  three  degrees  and 
this  is  not  sufficient  to  insure  safety.     The  best  method  to  follow  in 
laying  concrete  in  freezing  weather  is  to  heat  the  materials  before  mix- 
ing and  then  to  protect  the  work  from  freezing  until  it  has  set  for  a 
period  of  at  least  five  days. 

MONOLITHIC  BRICK  PAVEMENTS. 

102.  Monolithic  brick  pavement  construction  consists  principally 
in  laying  the  brick  directly  upon  the  soft  concrete  base  instead  of  lay- 
ing them  upon  a  sand  cushion  as  has  been  the  practice  for  many  years. 
The  concrete  base  for  this  type  of  pavement  construction  shall  there- 
fore be  very  uniform  in  consistency  and  slightly  dryer  than  is  normally 
used  in  concrete  road  construction.     It  should,  not,  however,  be  so  dry 
that  the  voids  will  not  readily  be  filled  and  the  work  finished  to  the 
desired   cross    section.      The   consistency   of    the    concrete    should   be 
such  as  to  allow  a  film  of  mortar  to  come  to  the  surface  of  the  con- 
crete after  it  has  been  tamped  three  or  four  times. 

103.  Finishing  Base  Course.     If  a  finishing  machine  is  used  on 
the  base  it  will  strike  off  the  surface  so  that  the  brick  may  be  laid 
directly  upon  the  soft  concrete.     In  a  few  instances  where  contractors 
have  been  unsuccessful  in  getting  a  uniformly  finished  base  they  have 
added  a  thin  covering  of  1 :3  dry  cement  and  sand.    The  dry  material 
fills  up  the  porous  spots  and  permits  a  uniform  bearing  for  the  brick. 
In  this  case  the  brick  shall  be  laid  and  tamped  before  any  initial  set 
takes  place  so  that  sufficient  moisture  may  be  drawn  from  the  concrete 


49 


base  to  thoroughly  saturate  the  film  of  dry  sand  and  cement  used 
on  the  surface.  In  general,  the  use  of  the  dry  sand  and  cement  film 
should  be  discouraged.  If  the  concrete  base  is  properly  proportioned, 
mixed,  and  finished,  the  best  results  will  be  secured  by  laying  the 
brick  directly  upon  the  concrete. 


Fig.  20.  Monolithic  brick  road  showing  concrete  base  and  brick  sur- 
face being  finished  with  a  mechanical  tamping  and  finishing  machine. 

104.  Finishing  Brick  Surface.     As  soon  as  the  brick  have  been 
laid  they  shall  be  carefully  culled  and  then  rolled  by  means  of  a  hand 
roller  weighing  not  less  than   600   pounds.     The  pavement  shall  be 
rolled  lengthwise,  crosswise,  and  at  a  45-degree  angle  and  all  rolling 
completed  before  the  initial  set  takes  place  in  the  concrete. 

Instead  of  using  a  hand  roller  for  finishing  the  brick,  a  very  light 
tandem  steam  roller  weighing  not  more  than  two  tons  may  be  used, 
if  such  a  unit  could  be  secured.  In  place  of  the  roller  an  extra  finish- 
ing machine  may  be  used  to  finish  the  brick  to  the  desired  cross  sec- 
tion. When  the  finishing  machine  is  used,  it  should  be  independent 
of  the  machine  used  on  the  concrete  base  and  should  be  operated  over 
the  surface  a  sufficient  number  of  times  to  insure  that  all  brick  are 
imbedded  properly  and  that  the  surface  is  made  smooth. 

105.  Grouting  Brick  Surface.     After  the  rolling  has  been  done, 
the  grouting  may  be  delayed  until  the  close  of  the  day.     It  is  neces- 
sary, however,  to  complete  each  day  the  grouting  for  that  day's  work 
and  not  allow  the  brick  to  remain  open  to  be  grouted  the  next  day. 
The  grouting  shall  extend  up  to  the  header  board  and  when  the  work 
starts  the  following  morning  the  first  four  or  five  feet  of  the  base 
should  be  finished  by  hand  tamping.    Extreme  care  should  be  taken  at 
the  construction  joints  to  see  that  the  brick  are  thoroughly  imbedded 
in  the  soft  concrete  base  and  that  no   irregularities   in  the   surface 
exist  in  the  finished  pavement.     The  grouting  of  the  brick  surface  is 
one  of  the  most  essential  parts  of  successful  brick  road  construction. 


50 

Extreme  care  shall  be  taken  to  see  that  the  grout  penetrates  to  the 
full  depth  of  the  brick.  It  usually  requires  three  independent  opera- 
tions to  thoroughly  grout  the  surface  of  a  brick  pavement.  The  final 
grouting  shall  be  squeegeed  very  carefully  and  all  surplus  mortar 
pushed  forward.  The  final  squeegee  shall  be  on  a  -io-degree  angle 
so  as  not  to  wipe  the  mortar  out  of  the  joints. 

106.  Uniform  Surface.     The  engineer  in  charge  of  brick  con- 
struction shall  follow  all  of  the  suggestions  outlined  under  "Concrete 
Pavements"  with  respect  to  securing  a  uniform  surface.     The  10-foot 
straight  edge  shall  be  used  constantly  on  the  brick  surface  to  see  that 
the  entire  pavement  is  finished  within  the  requirements  of  the  speci- 
fications. 

107.  Curing.     Within   a    few   hours   after   the   brick   pavement 
has  been  grouted,  it  shall  be  covered  with  frames,  canvas,  or  other 
material  to  protect  it  from  sun  and  wind.     The  specifications  require 
brick  pavements  to  be  cured  for  a  period  of  ten  days.     This  may  be 
done  in  the  same  manner  as  outlined  for  curing  concrete  pavements. 

BITUMINOUS  FILLED  BRICK  CONSTRUCTION. 

108.  Concrete  Base.     The  concrete  base   for  bituminous  filled 
brick  pavements  shall  be  tamped  and  finished  as  required  for  an  or- 
dinary concrete  road. 

109.  .Curing  Base.     The  concrete  base  shall  be  cured  for  a  per- 
iod of  at  least  ten  days,  following  the  same  methods  as  outlined  under 
"Concrete  Pavements."  The  base  for  a  bituminous  filled  brick  road  will 
usually  have  a  monolithic  concrete  curb.     This  will  be  of  assistance 
when  the  ponding  method  is  used  for  curing  the  pavement.     If  the 
ponding  method  is  not  used,  a  straw  covering  kept  wet  will  probably 
prove  most  satisfactory  as  this  method  will  permit  the  base   to  be 
cleaned  more  easily  preparatory  to  laying  the  cushion  and  brick. 

110.  Gravel    and    Macadam    Bases.     Old    gravel    or    macadam 
roads  may  in  a  few  instances  be  utilized  as  a  base  for  bituminous 
rilled  brick  pavement  surfaces.     If  such  a  base  is  used  it  should  have 
a  depth  of  at  least  eight  inches  and  a  width  slightly  greater  than  the 
width  of  the  finished  pavement.     The  ordinary  gravel  or  macadam 
road  will  usually  have  to  be  reshaped  before  laying  the  brick  surface. 
This  can  be  done  by  slightly  scarifying  the  surface,  adding  sufficient 
new  material  and  rerolling  it  to  secure  the  desired  cross  section. 

111.  Cushion.     The  cushion  may  be  of  sand  or  limestone  dust. 
In  the  case  of  a  macadam  or  gravel  base  the  cushion  will  have  to  be 
from  one  to  two  inches  in  thickness  to  take  up  the  irregularities  in 
the  surface  and  give  the  desired  finish.     The  cushion  on  a  concrete 
base  shall  not  be  thicker  than  one  inch  and  preferably  not  more  than 
three-fourths  of  an  inch.     In  every  case  the  sand  or  limestone  dust 
cushion  shall  be  thoroughly  compacted  so  that  when  it  is  struck  off 
true  to  the  cross  section,  the  brick  will  not  roll  to  an  uneven  finish. 
In  a  few  instances  a  mixture  of  sand  and  cement  in  the  ratio  of  1:3 
has  been  used  as  a  cushion,  and  in  other  cases  a  mixture  of  bituminous 


51 


material  and  sand.  The  object  of  the  cement  or  bituminous  material 
is  to  prevent  displacement  of  the  cushion  during  the  life  of  the  wear- 
ing surface. 

112.  Laying   and   Rolling   Brick.     The    bituminous    rilled   brick 
shall  be  laid,  culled  and  rolled  in  the  usual  manner  except  that  the  roll- 
ing shall  be  done  with  a  three  to  five-ton  tandem  roller.     It  is  prac- 
tically impossible  to  roll  the  road  at  right  angles  with  a  power  driven 
roller,  but  the  surface  can  be  thoroughly  rolled  longitudinally  and  at 
an  angle  of  45  degrees. 

113.  Bituminous  Filler.     After  the  rolling,  the  pavement  shall 
be  carefully  culled   for  broken  brick  and  the  surface   filled   with  a 
bituminous  filler.     If  a  sand  cement  cushion  is  used  it  shall  be  thor- 
oughly saturated  with  water  and  allowed  to  dry  out  before  the  pave- 
ment is  filled.     The  bituminous  filler  shall  be  applied  at  as  high  a 
temperature  as  is  permissible  and  on  days  when  it  is  warm  and  the 
brick  are  dry.    It  may  be  squeegeed  into  the  brick  surface  and  a  light 
film  of  material  left  over  the  entire  surface  of  the  pavement. 

114.  Curing  Surface.     No  curing  is   necessary   for  bituminous 
filled  brick  pavements  and  the  work  may  be  opened  to  traffic  within 
about  24  hours  after  the  pavement  is  finished. 

BITUMINOUS  CONCRETE  PAVEMENTS. 

115.  Finishing  Base.     The  base  for  bituminous  concrete  pave- 
ments shall  be  finished  with  a  finishing  machine  the  same  as  a  base 
for  a  brick  pavement  or  a  concrete  road.     After  being  finished  and 
just  prior  to  the  initial  set  of  the  concrete,  the  surface  shall  be  rolled 
with  a  corrugated  hand  roller.     The  rolling  shall  be  done  at  an  angle 
of  about  45  degrees  with  the  road  in  both  directions  so  that  the  surface 
will  be  roughened  to  a  depth  of  from  one-fourth  to  three-fourths  of 


Fig.  21.  Corrugated  hand  roller  used  to  roughen  concrete  surface 
for  a  bituminous  concrete  pavement. 


an  inch.  The  purpose  of  roughening  the  surface  is  to  insure  a  perfect 
bond  between  the  bituminous  wearing  surface  and  the  concrete  base. 
116.  Curing.  The  base  for  bituminous  concrete  pavements  will 
usually  have  a  monolithic  concrete  curb  which  will  assist  in  curing 
the  concrete  base  if  the  ponding  method  is  used.  If  this  method 
cannot  be  used  it  is  desirable  to  cure  by  the  use  of  a  straw  covering 
as  the  base  may  be  more  readily  cleaned  before  applying  the  wearing 
surface.  The  curing  shall  be  done  very  carefully  and  over  a  period  of 
at  least  ten  days. 


Fig.  22.  Dumping,  spreading,  and  rolling  bituminous  concrete  on  a 
concrete  base. 

117.  Concrete    Curb.     The    concrete    curb    on    the    bituminous 
rilled  brick  pavement  and  the  bituminous  concrete  pavement  may  be 
built  monolithically  by  using  a  special  finishing  machine  that  will  tamp 
and  finish  the  base  to  the  depth  of  the  curb  below  the  outside  forms. 
A  longitudinal  retaining  strip  of  angle  iron  or  wood  may  be  set  for 
the  inside  forms  of  the  curb  and  held  in  place  by  means  of  clamps 
which   will   hook   over  the   outside   forms.     The   space  between   the 
temporary  forms  and  the  outside  forms  may  then  be  filled  with  con- 
crete and  tamped  and  finished.     This  can  be  done  within  a  distance 
of  40  feet  behind  the  concrete  that  is  being  laid  in  the  base.    The  small 
amount  of  concrete  used  in  the  curbs,  therefore,  may  be  carried  back 
in  large  shovels  or  wheeled  back  in  wheel-barrows. 

118.  Binder  and  Wearing  Courses.     After  the  concrete  base  has 
been  cured  for  a  period  of  at  least  ten  days  and  in  addition  hardened 
for  a  period  of  at  least  twenty  days,  it  may  be  covered  with  the  binder 
course  which  shall  be   followed  immediately  by  the  top  or  wearing 
course.     The  total  thickness  of  the  binder  and  wearing  courses  does 
not  usually  exceed  three  inches.     The  binder  course  is  therefore  from 
one  and  one-half   to  two   inches   in  thickness.     The   same  type   and 
weight  of  tandem  roller  may  be  used  for  both  courses.     The  rolling 


53 

in  each  case  shall  be  done  immediately  after  the  material  is  uniformly 
spread  and  in  such  a  manner  that  the  finished  surface  will  be  per- 
fectly smooth.  The  rolling  as  well  as  the  spreading  of  the  bituminous 
concrete  should  be  done  by  experienced  men  to  insure  a  uniform 
wearing  surface.  In  no  case  shall  the  finished  surface  deviate  more 
than  one-fourth  inch  from  a  ten-foot  straight  edge. 

GRAVEL  ROADS. 

119.  Gravel  roads  are  built  either  by  the  trench  method  or  the 
feather-edge  method.  If  only  a  small  amount  of  gravel  is  to  be  used 
for  surfacing  or  building  a  road  (4  to  6  inches)  it  preferably  should 
be  placed  according  to  the  feather-edge  method.  If  a  greater  thick- 
ness is  to  be  applied,  better  results  will  be  obtained  by  building  it  accord- 
ing to  the  trench  method  or  at  least  by  constructing  it  so  that  the 
base  course  will  be  in  a  trench  and  the  wearing  course  feather-edged 
to  the  desired  width  of  the  improvement.  If  coarse  gravel  or  a  very 
large  portion  of  it  has  been  crushed,  it  is  advisable  to  follow  the  trench 
construction  method.  This  method  will  permit  the  surface  to  be  more 
thoroughly  rolled  and  bonded.  If  the  gravel  is  fine  (1  inch  and  under) 
and  contains  a  large  portion  of  clay  binder,  better  results  will  be  ob- 
tained by  following  the  feather-edge  method  as  it  is  practically  impos- 
sible to  roll  fine  material  with  any  success.  Gravel  roads  that  are  built 
according  to  the  feather-edge  method  can  usually  be  compacted  by  fre- 
quently dragging  the  surface.  When  fine  gravel  is  used,  it  is  desirable 
that  it  contain  not  over  25  per  cent  of  material  passing  a  one-fourth 
inch  screen  and  not  to  exceed  15  per  cent  of  clay  binder.  Gravel  con- 
taining less  binder  may  require  considerably  more  time  to  become  com- 
pacted under  traffic  but  the  road  obtained  will  prove  to  be  much  bet- 
ter after  it  has  once  become  consolidated. 


Fig.  23.  Trench  method  of  constructing  macadam  or  gravel  roads. 

120.     Trench  and  Feather-edge  Construction.     A  combination  of 
the  trench  and  feather-edge  methods  may  be  used  to  an  advantage  in 


54 

certain  instances.  The  bottom  part  of  the  gravel  road  for  about  two- 
thirds  the  width  of  the  finished  pavement  may  be  constructed  in  accord- 
ance with  the  trench  method.  After  the  bottom  course  has  been  spread 
and  thoroughly  compacted  the  entire  surface  may  be  shaped  and  the 
wearing  course  of  three  to  six  inches  applied  in  accordance  with  the 
feather-edge  method.  This  combination  of  methods  will  save  a  little 
gravel  and  prove  to  be  very  satisfactory. 


Pig.  24.  Gravel  road  constructed  by  the  feather-edge  method. 

121.  Crown.     The  crown  on  a  gravel  road  should  not  be  over 
three  inches  for  an  18-foot  width.     Excess  crown  will  force  traffic  to 
the  middle  of  the  road  and  this  will  result  in  unnecessary  rutting.     If 
the  gravel  road  is  properly  maintained,  a  very  light  crown  will  tend 
to  distribute  traffic  over  the  entire  surface  thereby  lengthening  the  life 
of  the  road.     In  general,  it  is  advisable  to  build  gravel  roads  fully  18 
feet  in  width  for  two  lines  of  traffic.     By  getting  a  wider  surface, 
traffic  does  not  become  concentrated  and  the  gravel  surface  will  hold 
up  under  less  maintenance. 

MACADAM  ROADS. 

122.  Macadam  roads  are  usually  constructed  by   following  the 
trench  method.     The  stone  preferably  should  be  applied  in  two  inde- 
pendent layers  of  about  five  inches  in  thickness  and  each  layer  thor- 
oughly rolled  and  bonded  with  screenings  or  bonding  gravel.     The 
stone  should  be  uniformly  graded  in  size  from  1^  to  2^  inches.    The 
roller  used  shall  be  a  10-ton,  3-wheeled  type.     Sufficient  rolling  shall 
be  done  to  key  the  stone  together  thoroughly  and  to  prevent  its  moving 
about  when  walked  upon.     Either  the  screenings  or  bonding  gravel 
shall  be  washed  into  the  voids  of  the  stone  at  the  time  of  construction 
or  the  road  shall  be  kept  closed  to  traffic  until  there  is  sufficient  rainfall 
to  accomplish  this  result.    The  finished  surface  of  a  macadam  or  gravel 
road  shall  not  deviate  more  than  one-half  inch  from  a  10-foot  straight 
edge. 


55 

123.  Crown.  The  crown  on  a  macadam  road  shall  not  exceed 
four  inches  for  an  18-foot  pavement.  The  small  crown  will  tend  to  dis- 
tribute traffic  over  the  entire  macadam  surface  thereby  increasing  its 
life  very  materially. 

Macadam  roads  can  be  maintained  by  applying  frequently  a  small 
amount  of  bonding  gravel  or  bonding  screenings.  If  the  surface  is 
allowed  to  become  bare  for  lack  of  bonding  material,  the  stone  will  soon 
become  dislodged  causing  the  surface  to  begin  to  ravel. 


BITUMINOUS  MACADAM  ROADS. 

124.  Bituminous  macadam  roads  are  built  somewhat  similar  to 
ordinary  macadam  roads  except  that  the  top  two  and  one-half  or  three 
inches  of  stone  are  penetrated  with  bituminous  material  (from  2  to  2*/2 
gallons  per  square  yard)  and  then  choked  with  stone  chips  or  torpedo 
gravel.     The  purpose  of  this  filler  is  to  hold  the  large  stone  in  place 
and  prevent  raveling  of  the  road  surface.    The  method  outlined  in  the 
specifications  should  be  followed  very  carefully  in  this  type  of  con- 
struction. 

125.  Surface  Treatment.     Many  macadam  and  gravel  roads  de- 
teriorate very  rapidly  under  motor  driven  traffic.     To  prevent  raveling 
it  is  necessary  continually  to  apply  additional  binder  to  the  surface 
such  as  screenings  or  bonding  gravel.    There  is  also  considerable  annoy- 
ance on  account  of  the  dust  rising  from  gravel  and  macadam  roads. 
Such  surfaces  are  therefore  improved  by  sweeping  off  all  surplus  fine 
material  and  applying  a  light  application  of  asphalt  or  tar  and  then 


Pig.  25.  Method  used  for  distributing  bituminous  material  for  sur- 
face treatment  of  macadam  and  gravel  roads  or  for  oiling  earth  roads. 

covering  the  surface  with  sand  or  stone  chips.  A  well  constructed 
macadam  road  may  be  surface  treated  with  considerable  success  in  this 
manner  and  maintained  in  a  condition  that  is  much  more  desirable  than 


56 


that  of  the  ordinary  macadam  road.  The  surface  mat  can  be  main- 
tained by  applying  annually  a  small  amount  of  bituminous  material 
and  stone  chips  or  torpedo  gravel. 


Fig.  26.  Condition  of  macadam  surface  after  first  application  of  one 
and  one-half  to  two  gallons  per  square  yard  of  bituminous  material  is 
applied.  This  treatment  to  be  followed  with  stone  chips  or  torpedo 
gravel  then  one-half  to  three-fourths  gallon  per  square  yard  and  an- 
other covering  of  stone  chips  or  gravel. 

126.  Surface   Treating   Gravel  Roads.     Very  little  success  has 
thus   far  been  attained  in  the  surface  treatment  of  gravel  roads  in 
Illinois.     The  principal   reason   for   this   is   that  most   of   the   gravel 
roads  contain  a  very  large  percentage  of   clay  binder  and  the  clay 
prevents  the  bituminous  material  from  properly  binding  and  holding 
the  gravel  surface.     Considerable  success  has  been  experienced,  how- 
ever in   oiling   gravel    roads   which   have   a   moderate   traffic   but   no 
heavy  truck  traffic.     The  paraffin  base  asphaltic  oils  having  a  40  to 
50  per  cent  residue  may  be  applied  to  such  roads  at  the  rate  of  about 
one-half  to  three-fourths  gallon  per  square  yard  of  surface.     The  oil 
should  be   spread   in  two   applications  and   each   covered   with   stone 
chips  ranging  in  size  from  one-half  to  three-fourths  of  an  inch.    After 
this  light  oil  has  permeated  most  of  the  clay  binder  and  the  surface 
has  formed  a  fairly  good  mat,  the  road  may  be  treated  with  a  better 
grade  of  asphalt  or  refined  tar  and  stone  chips  again  applied.     This 
method  will  build  up  a  mat  on  the  surface  of  a  gravel  road  that  will 
withstand  moderately  heavy  traffic.     This  type  of  construction  is  de- 
sirable for  secondary  roads  and  streets  and  particularly  roads  which 
have  considerable  pleasure  traffic. 

EARTH  ROADS. 

127.  Earth  roads  should  be  constructed  to  a  width  of  24  to  30 
feet  exclusive  of  the  ditches.    The  crown  should  be  from  6  to  12  inches, 
and  if  the  road  is  properly  maintained,  the  lighter  crown  will  prove 
much  more  desirable. 


57 

128.  Grading  Machinery.     Earth   roads  will  ordinarily  be  con- 
structed by  the  use  of  graders  having  a  blade  8  to  12  feet  in  length 
which  may  be  pulled  by  20  to  40-horse  power  gas  or  steam  engines. 
After  the  heavy  grading  work  has  been  done,  the  surface  may  be  shaped 
and  maintained  with  an  ordinary  drag,  light  grader,  or  leveler.     Where 
it  is  necessary  to  move  a  portion  of  the  earth  longitudinally  with  the 
road,  it  can  be  done  by  the  use  of  elevating  graders  discharging  directly 
into  dump  wagons  that  will  carry  the  earth  to  the  desired  location. 
On  heavy  cuts,  steam  shovels  can  be  used  to  an  advantage.     On  ordi- 
nary work,  Maney  scrapers,  wheel  scrapers,  fresnoes,  or  slips  may  be 
used  to  pull  the  earth  from  the  hills  into  the  low  places.     After  the 
earth  road  has  been  graded  so  that  it  will  properly  drain,  the  chief 
problem  is  that  of  maintenance. 

129.  Earth  Road  Maintenance.     The  earth  surface  will  become 
very  badly  rutted  and  out  of  shape  following  each  rain.     It  is  there- 
fore necessary  to  provide  for  constant  maintenance  to  keep  the  surface 
smooth  and  in  a  condition  that  it  will  shed  water.     The  maintenance 
can  be  best  handled  by  the  use  of  the  ordinary  road  drags  which  may 
be  either  of  the  wood  or  steel  type.     In  many  cases  the  Minnesota 
road  planer,  the  leveler,  or  the  three-way  drag  is  used,  but  most  any 
form  of  a  drag  will  prove  satisfactory.     The  main  object  is  to  keep 
the  surface  smooth  and  to  smoothen  it  at  times  when  the  operation 
is  most  effective. 

OILED  EARTH  ROADS. 

130.  Earth  roads  may  be  maintained  more  satisfactorily  by  one 
or  two  applications  of  road  oil  each  year.     Before  the  road  oil  is  ap- 
plied, the  earth  should  be  shaped  to  the  desired  cross  section  and  the 
surface  made  smooth  and  free  from  dust.    The  oil  should  then  be  ap- 
plied for  a  width  of  about  15  feet  at  the  rate  of  one-half  gallon  per 
square  yard  of  surface.    The  oil  shall  be  put  on  in  two  applications  of 
one-fourth  gallon  in  each  application.     If  considerable  time  is  allowed 
to  elapse  between  the  two  treatments,  better  results  will  be  assured.  The 
road  oil  for  the  first  application  shall  contain  from  45  to  55  per  cent 
asphaltum  residue  and  shall  be  applied  hot  so  that  it  will  thoroughly 
penetrate  the  earth  surface.     The  second  and  succeeding  applications 
may  be  of  slightly  heavier  consistency  (50  to  60  per  cent  residue).     In 
each  case  the  oil  shall  be  heated  so  that  it  will  thoroughly  penetrate 
the  road  surface  when  put  on.     The  first  treatment  of  road  oil  can 
ordinarily  be  spread  in  April,  and  the  second  in  June.     This  will  allow 
the  road  to  go  through  the  major  part  of  the  summer  free  from  dust 
and  mud.     A  fall  application  in  September  is  sometimes  desirable  al- 
though not  always  economical.     Fall  oiling  can  hardly  be  justified  on 
account  of  the  expense.     The  primary  object  of  the  oil  is  to  suppress 
the  dust  and  to  prevent  mud  through  the  summer  and  fall  months. 
In  general  therefore,   the  oil   shall  be   applied   in   the   spring   before 
the   dust    forms.      On   moderately   traveled   roads,    and    during   some 
mild   winters,  the   fall   oiling  may   prevent   mud   throughout   the   re- 


58 


mainder  of  the  year.     The  average  winter  in  Illinois,  however,  will 
cause  the  oiled  surface  to  break  through  under  heavy  traffic. 


Fig.  27.  Well  graded  and  oiled  earth  road. 

The  oiled  surface  can  be  maintained  satisfactorily  by  the  use 
of  a  light  drag  following  a  rain.  An  oiled  surface  that  has  become 
pitted  can  be  repaired  by  slightly  scarifying  the  entire  surface  of 
the  road  and  thoroughly  dragging  it  during  or  following  a  rain.  It 
should  then  have  another  light  treatment  of  oil  if  possible.  The 
cause  of  most  pit  holes  in  the  oiled  surface  is  that  the  road  surface  does 
not  absorb  the  oil  when  it  is  first  applied. 

SHOULDERS  AND  SIDE  DITCHES. 

131.  Cross  Section.     Properly  shaped  shoulders  and  side  ditches 
add  materially  to  the  life  of  an  improved  road  as  well  as  to  its  ap- 
pearance.   Earth  shoulders  shall  be  graded  to  a  uniform  width  from 
the  edge  of  the  pavement  and  sloped  sufficiently  to  drain  the  surface 
water  to  the  side  ditches  readily.    When  earth  shoulders  are  first  con- 
structed of  loose  material,  it  is  desirable  to  build  them  practically  level 
to  their  full  width.     After  the  earth  has  become  settled  they  will  us- 
ually have  the   slope  necessary  to  carry  off  surface  water.     If  the 
shoulders  could  be  thoroughly  rolled  or  compacted  during  construction 
they  could  be  built  to  the  standard  slope  shown  on  the  plans  but  this 
is  practically  impossible,  hence  they  must  be  built  up  level  and  al- 
lowed to  settle  to  the  desired  slope. 

132.  Side  Ditches.     The  side  ditches  preferably  should  be  made 
by  the  use  of  a  slip  scraper  or  a  specially  designed  grader  blade.    The 
back  slope  on  the  side  ditches  should  be  made  by  the  use  of  a  small 
grader  that  will  throw  some  of  the  material  towards  the  fence  line.    An 
abrupt  bank  on  the  back  slope  shall  not  be  allowed  as  this  material 
will  easily  cave  and  fill  the  ditches. 

133.  Hand  Work.     Extreme  care  shall  be  exercised  in  grading 
the  ditches  to  make  certain  they  will  drain  to  the  outlets  in  the  road. 


59 


It  is  not  necessary  to  require  hand  work  on  the  shoulders,  side  ditches, 
or  back  slopes  provided  the  contractor  is  capable  of  getting  satisfac- 
tory results  by  the  use  of  machines.  On  deep  cuts,  however,  it  may 
frequently  be  desirable  to  do  a  small  amount  of  hand  work  to  pre- 
vent unnecessary  sloughing  of  the  loose  materials  into  the  side  ditches. 


Fig.  28.  Showing  well  shaped  shoulder  and  side  ditch. 

134.  Finisihng   Shoulders.      Shoulders,    side   ditches,   and   back 
slopes  shall  be  finished  complete  just  as  soon  as  the  pavement  is  ready 
to  be  opened  to  traffic.     Delay  in  finishing  the  shoulders  and  ditches 
may  cause  serious  accidents  when  the  road  is  opened  to  traffic,  and 
may   further  cause  considerable   delay  in  final  payment  to  the  con- 
tractor on  account  of  the  work  not  being  completed  and  ready  for 
final  acceptance.     As  soon  as  the  grading  has  been  completed  to  the 
desired  cross  section,  the  shoulders  shall  be  seeded  in  accordance  with 
the  specifications  to  prevent  unnecessary  erosion. 

135.  Entrance   Culverts.     All   farm   entrance  culverts   shall  be 
built  after  the   shoulders   and   side   ditches   have   been    formed   with 
the  grading  machine.     If  the  culverts  are  constructed  in  advance  they 
are  frequently  out  of  alignment  and  not  built  to  the  grade  of  the 
ditch  line.    If  this  practice  is  followed,  the  contractor  will  be  required 
to  do  considerable  hand  work  adjacent  to  the  culverts  to  properly 
shape  the  shoulders  and  ditches  and  thus  add  to  the  cost  of  his  work. 

ACCEPTANCE  OF  WORK. 

136.  A  road  is  ready  for  final  acceptance  when  the  shoulders, 
side  ditches,  and  back  slopes  have  been  properly  finished  and  seeded, 
and  all  incidental  work  in  connection  with  the  pavement  is  completed 
in  accordance  with  the  plans  and  specifications. 

137.  Completing  Details  of  Work.     The  specifications  stipulate 
that  immediately  upon  the  satisfactory  completion  of  a  section  of  road, 


60 

and  upon  the  written  approval  of  same  by  the  engineer,  the  contractor 
shall  be  relieved  of  any  requirements  for  further  work  on  such  sec- 
tion. It  is  therefore  suggested  that  contractors  complete  all  details  of 
their  work  as  they  go  to  permit  a  partial  acceptance  and  full  payment 
on  the  completed  portion.  In  a  great  many  cases  final  payment  on 
both  a  partial  acceptance  and  a  final  acceptance  has  been  withheld  on 
account  of  minor  work  remaining  undone,  the  value  of  which  may 
amount  to  but  a  few  hundred  dollars.  Such  negligence  on  the  part  of 
the  contractor,  therefore,  seriously  ties  up  considerable  money  that  may 
be  due  him. 

138.  Certified  Checks.     In  a  few  instances  where  only  a  small 
amount  of  work  remains  to  be  done  to  secure  final  acceptance,  certi- 
fied checks  have  been  accepted  in  lieu  of  unfinished  work.    This  prac- 
tice, however,  will  not  be  tolerated  except  in  instances  where  the  con- 
tractor shows  sufficient  evidence  that  he  has  not  been  able  to  complete 
the  small  details  of  his  work  for  causes  beyond  his  control.     When 
certified  checks  are  submitted  they  shall  not  exceed  approximately  $500 
for  the  section  of  work  under  consideration  for  acceptance. 

139.  Partial  Acceptance..     In  the  case  of  a  partial  acceptance  of 
a  section,  it  should  be  kept  in  mind  that  the  Department  cannot  accept 
any  portion  of  a  contract  unless  the  portion  finished  is  approximately 
one  mile  in  length  and  will  become  of  some  service  to  the  traveling 
public  when  accepted  and  opened  for  use. 

PAYMENT  ESTIMATES. 

140.  The  district  engineer  shall  submit  to  the  Division  of  High- 
ways, Bureau  of  Construction,  not  oftener  than  twice  each  month  an 
estimate  in  triplicate  of  the  work  completed  by  the  contractor  on  which 
the  contractor  shall  be  paid  90  per  cent  of  the  estimate,  the  remaining 
10  per  cent  to  be  held  in  reserve  until  the  completion  and  acceptance 
of  the  entire  work. 

The  following  instructions  shall  be  followed  in  making  out  pay- 
ment  estimates: 

1.  Payment  estimates  shall  be  made  up  from  the  contract 
and  not  from  the  project  agreement  of   the  section  under  con- 
sideration. 

2.  All   estimates    shall   show   quantities   completed   to   date 
including  extras  and  in  all  cases  the  completed  quantities  multi- 
plied by  the   unit   prices   shall   equal   the   amount   showrn   in   the 
"Value  Completed"  column. 

3.  All  estimates,  except  semi-final  estimates,  shall  show  the 
total  quantities  as  awarded. 

4.  All  estimates,  except  semi-final  estimates,  shall  show  the 
total  quantities  added  or  deducted  opposite  the  corresponding  item 
of  work. 

5.  The  value  of  extras  and  deductions  shall  be  shown  in  the 
proper   columns   but   added   or   subtracted   as    the    case   may   be 
to  the  total  value  of  the  contract.     Additions  or  deductions  affect 
the  contract  price  and  the  total  amount  eventually  due. 


61 

6.  The  total  value  of  each  item  as  awarded  need  not  be 
shown  except  in  the  final  estimate. 

7.  Allowances   for  materials  in  storage  shall  be  shown  in 
the  Payment  Estimate  record.     Materials  stored  shall  be  on  the 
cumulative  basis  and  shall  show   in  the   respective  columns   the 
quantity  of  material  received,  used,  and  on  hand.     Requests  for 
reimbursement  for  materials  stored  shall  be  accompanied  by  the 
receipted  bills  or  itemized  statement  and  affidavit  as  outlined  in 
"Payment  for  Materials." 

8.  Allowances  for  excess  freight  and  war  tax  shall  be  shown 
under  "Miscellaneous   Credits."      Such  allowances   shall  also  be 
accompanied  by  an  itemized  statement  and  affidavit  as  outlined 
in  "Freight  Increases  and  Reductions." 

9.  The  10  per  cent  retention  shall  not  be  made  from  ma- 
terials in  storage  or  from  excess  freight  or  war  tax. 

10.  No  allowances  shall  be  included  in  semi-final  estimates 
for  materials  stored  or  for  excess  freight  and  war  tax. 

11.  Make  a  regular  engineer's  payment   estimate  covering 
the  portion  of  the  work  under  consideration  before  a  semi-final 
estimate  is  made.    Semi-final  estimates  shall  be  made  on  the  same 
form  as  the  regular  monthly  estimates. 

12.  Attach    to   the    final    estimate    an    itemized    list    of    all 
cement  shipments  received  since  the  previous  estimates. 

13.  With  semi-final  and  final  estimates  submit  final  inspec- 
tion report,  affidavit,  and  bills  for  all  miscellaneous  extra  work. 
With  semi-final  estimates  a  release   from  the  bonding  company 
shall  be  submitted  as  outlined  under  "Semi-final  Estimates." 

14.  When  inspectors  submit  monthly  estimates  to  the  dis- 
trict engineer,  they  shall  be  accompanied  by  a  letter  of  explanation 
showing  how  the  quantities  on  the  estimate  were  arrived  at. 

141.  Payment  for  Materials.  The  Department  may  at  its  dis- 
cretion pay  for  any  or  all  materials  purchased  and  delivered  f.  o.  b.  the 
railroad  siding  provided  such  material  meets  the  requirements  of  the 
district  engineer.  The  amount  thus  paid,  however,  shall  go  to  reduce 
estimates  to  the  contractor  as  the  material  is  used  in  the  work.  If 
the  contractor  desires  to  ask  for  payment  on  such  materials  he  shall 
submit  to  the  engineer  the  receipted  material  bills  in  triplicate,  or,  if 
he  desires  to  retain  the  bills  he  may  submit  an  itemized  statement  of 
the  bills  together  with  an  affidavit  (similar  to  Fig.  29,  Form  M-88) 
certifying  to  the  quantity  and  cost  of  the  material  f.  o.  b.  the  railroad 
siding.  On  contracts  awarded  under  the  1919  specifications,  it  is  nec- 
essary to  have  a  release  from  the  contractor's  bondsman  granting  per- 
mission to  the  State  Division  of  Highways  to  pay  for  materials  de- 
livered. Such  release  or  supplementary  agreement  is  to  be  attached 
to  the  contract  on  file  in  the  main  office.  The  blank  form  of  release 
should  be  obtained  from  the  Springfield  office  and  sent  in  previous 
to  the  forwarding  of  the  estimates  in  order  to  have  them  approved 
and  signed  by  the  Department  in  advance  of  the  time  the  estimate  is 
received  so  that  payment  for  the  work  will  not  be  delayed.  The  1920 


62 

and  1921   specifications  provide   for  payment  of   materials,  therefore 
no  release  is  required. 

142.  Freight  Increases  and  Reductions.     In  accordance  with  the 
specifications,    contractors   will   be    allowed   all    increases    in    freight 
effective  from  the  date  of  the  receipt  of  bids.     Contractors  making 
claim  for  payment  of  increased  freight  shall  submit  on  Fig.   30  an 
itemized  statement  of  the  cars  received  on  which  reimbursement  is 
requested.     He  shall  also   submit  published  tariff   rates   or   sufficient 
evidence  to  show  the  rate  in  effect  on  the  date  of  the  bids  and  the 
rate  and  date  of  the  various  increases.     The  itemized  statement  shall 
be  accompanied  by  an  affidavit,  similar  to  Fig.  31. 

In  case  a  reduction  in  freight  is  made,  similar  forms  shall  be  used. 

143.  Semi-final  Estimates.     When  a  portion  of   a  section  in  a 
specific  contract  is  entirely  completed  and  ready  for  acceptance,  the 
district  engineer  may  submit  to  the  Springfield  office  a  semi-final  esti- 
mate which  will  allow  the  10  per  cent  that  has  been  withheld  in  prev- 
ious estimates  on  the  completed  work.     Semi-final  estimates  shall  also 
be  accompanied  by  a  final  inspection  report  by  the  district  engineer 
and  an  affidavit  from  the  contractor  certifying  that  all  sums  of  money 
due  for  labor,  material,  machinery,  etc.  have  been  paid.     A  release 
from  the  bonding  company  authorizing  payment  in  full  for  the  por- 
tion completed  shall  be  mailed  to  the  main  office  before  payments  can 
be  made  on  a  semi-final  estimate.     This  release  shall  be  submitted  on 
Fig.  32,  Form  M-62. 

144.  Affidavit.     When  an  entire  road  or  a  portion  of  a  road  is 
ready  for  final  acceptance,  all  money  due  the  contractor  shall  be  paid 
him  provided  he  will  furnish  an  affidavit  similar  to  Fig.  33,  Form  141 
showing  that  all  sums  of  money  due  for  labor,  material,  apparatus,  fix- 
tures, or  machinery  furnished  for  the  improvement  in  question  have 
been  -paid,  or  that  the  person  to  whom  money  may  be  due  consents  to 
final  payment  being  made  to  the  contractor. 

FORM  OF  STATEMENT  AND  AFFIDAVIT  FOR  MATERIALS 

STORED. 

The  following  form  should  be  followed  by  all  contractors  who  ex- 
pect reimbursements  on  materials  placed  in  storage. 

ITEMIZED  MATERIAL  STATEMENT. 

Materials  received  from 192....  to 192....  are  as  follows: 

....tons  of  Gravel  @  per  ton  f.  o.  b = 


shipping  point 

Sand      @  "      "         "       

shipping  point 

Stone     @  "      "         "       

shipping  point 

Total 


63 

FREIGHT. 

"      "   Gravel  @  "      " 

destination 
"  "  Sand  @  .. 

destination 
"  "  Stone  @ "  "  "  - 

destination 
Total 

Grand  total 

Approved Contractor. 

....Resident  Engineer  or  District  Engineer 


STATE  OF  ILLINOIS, 
County  of.... 


y  ss. 


AFFIDAVIT. 
Mr : being  first  duly  sworn,  deposes 

and  says  that  he  represents  the Company 

and  is  authorized  to  make  the  following  statement: 

That  the  above  named  materials  (or  materials  listed  on  attached  state- 
ment) have  been  received  and  stored,  to  the  satisfaction  of  the  representa- 
tive of  the  .State  Division  of  Highways  for  use  in  the  construction  of  Section 

Project  Route  

That  the  sum  of  $ has  been  paid  the 

R.  R.  for  freight  on  said  material  and  that  the  sum  of  $ 

has  been  paid  the.. Company  for  said  materials 

f.  o.  b 

Further,  that  this  affidavit  is  made  for  the  purpose  of  obtaining  pay- 
ment on  said  materials  in  accordance  with  supplementary  contract  dated 

and  supplementary  letter  by  the  Depart- 
ment of  Public  Works  and  Buildings  dated  January  22,  1920. 


Contractor. 
By 

Subscribed  and  sworn  to  before  me  this day  of 

....192.... 


(Notary  Seal) 

Notary  Public 

Note:  The  above  affidavit  shall  be  made  on  the  itemized  bill  or  attached 
to  the  statement  submitted. 

Fig.  29 

Form  M-88 


64 


MEMORANDUM    OF     CARS    RECEIVED. 

Section , County,   Proj.    or   Route 

Kind  of  material From  whom  purchased , 

Shipping   Point ,   Name   of   R.   R 

Published  tariff  rate Date  on  which  increase  or  reduction 

became  effective.... 


o 
n. 


te 
h 


P 


moun 
incre 
reduc 


Keep  sand,  stone,  steel,  etc.  separate  giving  the  company  and  railroad 
over  which  material  was  shipped. 

List  cars  according  to  dates  so  that  each  list  will  show  the  complete 
number  of  cars  received  during  any  particular  interval. 

Make  the  statement  in  triplicate.  Attach  affidavits  to  lists  and  mail 
to  district  engineer. 

Engineer's  O.  K.  and  railroad  agent's  approval,  when  possible  to  secure 
it,  should  be  shown  on  each  statement. 

O.  K... 


Resident  Engineer 


Contractor 


District  Engineer 


R.  R.  Agent 


FIG.  30. 


G5 


State  of  Illinois 
County  of.... 


AFFIDAVIT. 

Mr being  first  duly  sworn, 

deposes  and  says  that  he  represents  the 

Company  and  is  authorized  to  make  the 

following  statement. 

That  the  above  named  materials  (or  materials  listed  on  attached  state- 
ment) have  been  received  and  the  war  tax  and  freight  as  indicated  have 

been  paid  for  materials  used  in  the  construction  of  Section , 

Project ,   Bond   Issue  Route 

Further,  that  this  affidavit  is  made  for  the  purpose  of  obtaining  refund 
from  the  State  for  war  tax;  the  10-cent  reduction  in  freight  which  the  con- 
tractor was  supposed  to  receive  on  road  building  material  and  all  increases 
in  freight  rate  since  the  date  of  the  contract  and  particularly  since  August 

26,   1920   in  accordance   with   contract   dated 


Contractor. 

By 

Subscribed   and   sworn   to   before  me   this , 

day   of 192 

[NOTARY  SKAI..  | 

Notary  Public. 
FIG.  31 

RELEASE   FOR    SEMI-FINAL   ESTIMATE. 

The  Department  of  Public  Works   and  Buildings  is  hereby   authorized 
and  requested  to  make  payment  in  full  to  the  contractor     upon     contract 

named  below  for  such  portion  of  the  same  as  may  be  completed  by.... 

and  approved  by  the  Chief  Highway 

Engineer,  or  his  duly  authorized  representative. 

This  authorization  to  be  attached  to  our  bond  issued  to  the  Department 

of  Public  Works  and  Buildings  covering  the  contract  of 

for  Project ,  Section in 

County,  and  is  to  become  a  part  of  said  surety 

contract. 


By 

FIG.  32,  FORM  M-62. 


66 

STATE   OF  ILLINOIS  -j 

COUNTY   OF j  SS> 

CONTRACTOR'S   AFFIDAVIT. 

haying  completed  the  improvement  of  a aid 

road  known  as  Section , 

County,  Project ,  Route ,   in   accordance   with  the  plans, 

specifications,  proposal  and  bid  relating  thereto,  as  provided  for  in  contract 

approved 192 ,   being   duly 

sworn  on  oath,  doth  say  that  all  sums  of  money  due  for  any  labor,  material, 
apparatus,  fixtures  or  machinery  used  in  such  construction,  and  that  all 
damages,  direct  or  indirect,  suffered  or  claimed  on  account  of  such  con- 
struction or  improvement,  have  been  paid. 


By 

Subscribed  and  sworn  to  before  me  this day 

of....  ....192.... 


Notary  Public. 
FIG.  33.     FORM  No.  141. 


(SUGGESTED   FORM   OF   BILL   FOR   EXTRA   WORK.) 


Department  of  Public  Works  and  Buildings 
Division   of  Highways,   Dr. 

to 


Contractor. 


Contractor. 


Examined   and   found   correct: 


Resident  or  District  Engineer. 

FIG.  34. 


68 

DETOUR  AND  BARRICADE  SIGNS. 

145.  All  detour,  slow  and  barricade  signs  shall  be  erected  and 
maintained  by  the  engineer  in  charge  of  the  road  or  bridge  being  im- 
proved. All  signs  necessary  to  guide  the  traveling  public  around  any 
highway  that  has  been  closed  for  improvement  shall  be  secured  from 
your  district  engineer. 

All  signs  erected  shall  be  securely  fastened  to  a  solid  background 
by  means  of  paste  or  tacking  completely  around  the  margin  at  inter- 
vals of  not  more  than  three  inches.  If  thin  paper  signs  are  supplied 
they  may  be  pasted  to  a  board  background,  if  the  heavy  cardboard  sign 
is  supplied  it  will  have  been  dipped  in  paraffin  or  shellac  to  protect  it 
from  the  action  of  the  weather. 

146.  Slow   Sign.     The   slow    sign,    (Fig.    35)    shall   be    erected 
on  a  post  set  in  the  outer  edge  of  the  shoulder  about  400  feet  ahead  of 
the  barricade.     The  top  of  the  sign  shall  be  about  4  feet  from  the 
ground  line,  the  post  supporting  the  sign  shall  not  be  smaller  than  a 
2x4  and  shall  be  set  at  least  2  feet  into  the  ground. 

147.  Road  Closed.     The  road  closed   sign,    (Fig.   36)    shall  be 
erected  on  two  substantial  posts  set  in  front  but  independent  of  the 
barricade.   The  posts  shall  be  at  least  2"  x  4"  x  7'  long  and  set  two  feet 
apart  and  at  least  two  feet  into  the  ground  at  a  point  where  they  will 
not  be  disturbed  by  traffic.    On  the  "Road  Closed"  sign  you  shall  print 
carefully  sufficient  information  to  guide  the  traveling  public  around  the 
road  that  is  closed  for  improvement,  ie.   N-2  mi ;  W-3  mi ;   S-2  mi. 
brings  you  back  onto  the  road. 

1  IS.  Detour  signs.  A  detour  sign  shall  be  fastened  immediately 
below  the  "Road  Closed"  sign,  with  its  arrow  pointing  in  the  direction 
of  the  detour.  Detour  signs  shall  be  erected  in  such  way  that  traffic 
going  in  both  directions  may  readily  follow  the  detour.  There  shall 
be  at  least  two  signs  at  all  cross  or  intersecting  roads  and  a  sign  along 
the  road  at  least  every  mile.  If  existing  poles  are  not  located  in  posi- 
tion desired  substantial  posts  shall  be  securely  set  at  the  desired  points 
and  the  "Detour"  signs  securely  nailed  to  them.  The  post  shall  be  set 
so  that  the  traffic  that  is  being  detoured  may  readily  see  the  sign  and  not 
fail  to  make  the  proper  turn.  Figure  38  will  serve  as  a  guide  in  the 
location  of  the  different  signs. 

149.  Purchasing  and  erecting.     Unless  otherwise  instructed  by 
your  district  engineer  you  will  make  a  memorandum  of  the  sign  boards 
and  posts  needed  to  d'etour  the  work  at  all  times  during  its  construc- 
tion.   You  will  then  go  to  the  nearest  lumber  yard  and  secure  sufficient 
lumber  for  the  signs  needed  and  get  a  receipted  bill,  which  you  may 
turn  in  at  the  same  time  you  forward  your  expense  account.    The  con- 
tractor will  probably  loan  you  the  necessary  tools  to  make  and  erect 
the  signs.     If  extra  help  is  needed  hire  a  man  and  get  a  receipt  for 
the  amount  paid. 

150.  Maintenance  of  Signs.     From  time  to  time  determine  the 
signs  that  are  actually  needed  to  detour  the  traffic  around  that  portion 
of  the  road  that  is  closed.     Try  and  check  all  signs  each  day  or  at 


69 

least  twice  each  week  to  see  that  they  are  in  place.  No  excuse  will  be 
accepted  for  not  having  all  signs  erected  and  maintained  in  such  way 
that  inconvenience  to  the  traveling  public  will  be  minimized. 

151.  Maintenance  of  detour  road.     If  the  road  on  which  you 
have  chosen  to  detour  traffic  is  in  need  of  dragging  or  maintenance, 
get  in  touch  with  the  local  township  commissioner  and  exert  your  in- 
fluence to  have  the  road  dragged.     It  might  be  well  to  determine  your 
detours  as  soon  as  you  arrive  on  the  job  and  consult  the  highway  com- 
missioner concerning  their  maintenance.     This  will  give  the  commis- 
sioner a  more  active  interest  in  the  construction  of  the  road  and  will 
result  in  his  cooperation  from  the  start. 

BARRICADES. 

152.  It  is  the  duty  of  the  engineer  to  see  that  the  contractor 
puts  up  proper  barricades,  maintains  them   during  construction  and 
completely  removes  them  from  the  site  before  final  acceptance. 

Barricades  should  be  constructed  in  the  following  manner :  Posts 
shall  be  erected  at  5'  centers  entirely  across  the  roadway  and  at  least 
one  line  of  2"  x  6"  timber  spiked  near  the  top  of  the  posts.  The  posts 
shall  be  6"  x  ?'  long,  of  sound  material  and  set  at  least  3'  into  the 
ground.  In  case  it  is  necessary  to  permit  people  living  along  the  road 
entrance  through  the  barricade,  opening  shall  be  provided,  preferably 
near  the  center  of  the  roadway  and  a  substantial  gate  erected.  The 
entire  barricade  shall  then  be  whitewashed  or  painted  white.  The  con- 
tractor shall  be  required  to  see  that  the  barricades  are  locked  and  that 
proper  individuals  are  supplied  with  keys  until  the  final  completion  of 
the  road.  The  contractor  may  arrange  with  each  property  owner  liv- 
ing along  the  road  to  provide  his  own  key  and  padlock  which  may  be 
attached  to  the  gate.  When  this  arrangement  is  made  each  padlock 
forms  a  link  of  the  locking  chain.  If  the  barricade  is  to  remain  for 
any  considerable  length  of  time,  such  as  through  a  winter,  it  shall  be 
painted  with  black  stripes. 


70 


ROAD 
CLOSED 

BY  ORDER  OF— 

CLIFFORD  OLDER,  CHIEF  HIGHWAY  ENGINEER 

VIOLATORS  SUBJECT  TO  ARREST 


FINE-   IMPRISONMENT 

OR    BOTH 


OPEN  ONLY  TO  RESIDENT  AND  CONTRACTOR'S  TRAFFIC 

FOLLOW  MARKED  DETOUR 

Engineer  in  Charge  Will  indicate  Exact  Routing  of  Detour  Giving  Mileage  and  Direction 
Road   Closed    Sign   as   furnished    by    Department. 

ROAD 
CLOSED 

BY  ORDER   OF— 

CLIFFORD   OLDER,   CHIEF  HIGHWAY  ENGINEER 

VIOLATORS  SUBJECT  TO  ARREST 


FINE,   IMPRISONMENT 
OR    BOTH 


OPEN  ONLY  TO  RESIDENT  AND  CONTRACTOR'S  TRAFFIC 

FOLLOW  MARKED  DETOUR 

West  2  mi.  South  2  mi.  East  2  mi. 
back  to  Main  Road] 

Engineer  in  Charge  will  Indicate  Exact  Routing  of  Detour  Giving  Mileage  and  Direction 

Road   Closed    Sign   showing    Engineers    notations. 
Fig.    35. 


SLOW 


BARRICADE-400FT 


STANDARD    WARNING    SIGN    FOR    BARRICADES 

Fig.    36. 


'72' 


DETOUR    FOR     ROUTE. 


-3j.no a 


STANDARD  DETOUR  SIGN  AS  FURNISHED  BY  DEPARTMENT 


DETOUR  JOR  J*PUTE_ 

L/MCOLN  HJQHMtY 


STANDARD  DETOUR  SIGN  SHOWING  ENGINEER'S 
NOTATIONS  BEFORE  ERECTING 


NOTE— Engineer  in  charge  will  indicate  before  erecting-  the  sign,  the  Route  num- 
ber, name  of  Trail,  its  Emblem  if  the  road  has  a  name  and  emblem,  the  next  town 
and  County  Seat  or  main  City  on  the  road. 


Fig.  37. 


Map  showing  Position  of  Barricade  and  Detour  Signs. 
Fig.  38. 


Syracuse,  N.  Y. 
PAT.  JAN,  21,  1908 


454213 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


